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Repair & restoration

Repair and restoration — power supplies, capacitors, keyboard membranes, dead machines, diagnostics, recapping.

190 threads · 1412 messages · 2002-11-12 → 2026-10-18

Most repair knowledge in the group comes from Carl Miles, who fixed Timex machines in the 1980s and wrote up his bench work in detail. His December 2023 thread on Ian's TS2068 and Ryan Gray's two machines covers socketed RAM, bodge wires, desoldering and, for Ryan's original 2068, replacing all six memory chips and the Z80. He also turned Ryan's 30-year-old donor 2068 into a test machine. The ZX Spectrum 48K from the Bill Miller collection was a longer case. It booted to black and white rectangles, the ZX Spectrum Diag Cart ran no tests, and a probe slip killed the -5V rail. Carl measured every electrolytic, and the thread ended up covering the 9V line that the ZX Printer, Interface 1 and Microdrives draw from the expansion bus. For Randy Kindig's "Toasted TS2068", which showed only bars on screen after overheating at VCFMW 18, Eduardo Fuentes suggested feeling the lower RAM chips for heat. Carl explained that a working display means the SCLD and power rails are fine and the CPU is not running code, which leaves the crystal, CPU, ROM/EXROM, upper RAM or a shorted bus as suspects. Michael Druckenmiller added a bent IC pin in a socket. For a 2013 black-screen 2068 that still beeped, Eduardo pointed to the UA78L12 regulator, the LM1889 in the modulator and the upper 4416 RAMs (U12/U13, U17/U18), and described testing by piggybacking a known-good chip.

Power is the recurring weak point. Neil C. quoted a January 1989 UPDATE warning that the 5V 1A regulator was overloaded once peripherals were added, and Adam Trionfo's divMMC/Twister boot hangs led to a thread on replacing the 15V brick. Richard Burt used Jameco part 191652 (15VDC 1A), Carl explained the original supply's design, and Claudius advised two smaller filter capacitors over one large one. Video noise has the same root cause. In 2009 Vsevolod (vbtinfo) traced it to switching pulses on the +5V line reaching the SCLD (U3) and fed U3 from its own 7805. David Anderson's how-to-fix-2068-video-output article (R-78E5, 7812) was the basis of Frederic Freakazoid's 2022 recap of four machines, and David attributed the AY hiss to the op amp sharing a die with the switching regulator. On recapping, Carl's view is that the 2068's Samyoung electrolytics rarely fail. His LCR-meter readings of Adam's alternate 2068 found every cap good, with C41 and C60 marginal, and he only replaces caps that measure bad, such as C20 on one of Mowgli's TS1500s.

Smaller fixes: John Lech's silent 2068 (AY chips from David's Andertone store, and Retroleum Spectrum speakers as replacements for the 45-ohm original), TS1000 membranes from RWAP and ZX Renew, a VLA81 ULA replacement for Carlos Nunez's TS1000, Adam's dead ZX8-CCB composite mod, and RichJ's point that TS2040 print darkness follows the 24VAC supply and line voltage. Several threads only drifted into repair: the cartridge-test thread (OUT 244,3) became a cartridge inventory, Josef Jelinek's PCB-update question became a discussion of clone boards, and the ABQ meeting, TS1000-to-TS1500 conversion, CZ2000 purchase and ZX80 TV-tuning threads each touch on fixes in passing.

Key threads

All threads (190)

↳ marks a thread where this topic begins mid-conversation — the link jumps to the message where it starts.

Thread Msgs Activity Started by
⭐ ZX Spectrum 48K Repair - Jan 2024 - Ryan got a ZX Spectrum 48K from the Bill Mil 📎 65 💬 2024-02-13 Carl Miles
⭐ ABQ User Group "Meeting" - Sat. Feb. 25, 2023 ↳ #2965 📎 47 💬 2023-05-16 Adam Trionfo
⭐ Test for a non-working Cartridge? 41 💬 2011-08-11 Jack Boatwright
⭐ Regarding Improving Stock Video 📎 31 💬 2023-01-15 Frederic Freakazoid
⭐ TS1000 -> TS1500 Conversion Project 📎 31 💬 2024-02-22 Carl Miles
⭐ TS2068 Repairs Dec 2023 -- Ian's Machine and Ryan's two TS2068 machines 📎 30 💬 2024-01-07 Carl Miles
⭐ Digest Number 261 28 💬 2005-07-09 James Diffendaffer
⭐ Any TS 2068 main PCB updates? 📎 25 💬 2024-08-25 josef.jelinek
⭐ I Got My Spectrum divMMC Today! ↳ #698 📎 25 💬 2022-01-30 Adam Trionfo
⭐ Slightly off topic… TS1000 Help 📎 24 💬 2024-06-23 Patrick Leclerc
⭐ Video Blurry; was: TS 2068 - Sound/Hissing Problem 24 💬 2009-09-16 Richard Atkinson
⭐ T/S 2068 Power Supply Replacement 📎 23 💬 2022-02-22 David Anderson
⭐ My Alternate T/S 2068 Computer - Recapping? 📎 22 💬 2026-01-15 Carl Miles
⭐ TS2068 Sound Issue 📎 21 💬 2024-01-25 Carl Miles
⭐ Toasted TS2068 📎 18 💬 2023-09-14 Floppy Days Podcast - Ra
⭐ Picked these up recently from Argentina... 📎 16 💬 2024-07-09 Carl Miles
⭐ TS 2068 Video Problem 15 💬 2013-04-28 mark_ull
⭐ A glorious day! 📎 15 💬 2022-03-31 Adam Trionfo
⭐ TS2068 working / not working Catridge dck files 📎 15 💬 2023-06-08 Retronerd
⭐ 2068 Video (color) problem... 14 💬 2005-12-12 Φοίβος Ρ. Ντόκος
⭐ Tilez [from Ryan's old tapes] ↳ #3007 📎 14 💬 2023-03-20 Ryan Gray
⭐ JLO Disk Interface 📎 14 💬 2022-01-28 Willie Jones
⭐ TS1000/1500/ZX81 power supply 📎 13 💬 2025-09-16 Carl Miles
⭐ Issue with a TS 2068 📎 12 💬 2026-06-03 David Laffineuse
⭐ Terminator 1000 - batery powered Timex 1000 ↳ #6713 📎 12 💬 2024-07-01 Greg Skuza
⭐ Composite TVs and Monitors 📎 12 💬 2024-01-17 andy
⭐ TS1500 refirb 11 💬 2026-09-29 Joe VandeZande
⭐ Help with T/S 2068 Repair 📎 11 💬 2024-05-30 patrick.jl.leclerc
⭐ Looks like I found the documentation for my Diagnostics Cartridge... 📎 11 💬 2024-05-28 Carl Miles
⭐ T/S Video Board/Monitor Questions 11 💬 2025-10-31 Adam Trionfo
⭐ TS1500 Keyboard Membranes 11 💬 2009-10-28 Timex
⭐ Timex/Sinclair 1000 RF out to TV 📎 10 💬 2022-12-22 Ryan Gray
⭐ TS2068 ROMS 📎 9 💬 2026-05-20 Joe VandeZande
⭐ TS2068 Power supply 📎 9 💬 2014-01-17 Richard Burt
⭐ Keyboard Membranes 9 💬 2010-12-21 Rich M
⭐ Why does the TS2040 use 24v? ↳ #8559 9 💬 2025-09-30 Josef Jelinek
⭐ Power Circuitry Replacement 9 💬 2023-12-26 David Anderson
⭐ ROM replacement services 9 💬 2007-05-09 Jarek Adamski
⭐ TS1500 and 16k RAM pack 📎 8 💬 2023-05-16 Ryan Gray
⭐ TS2068: R69 value in composite video output circuit? 📎 8 💬 2023-08-24 Brett Hallen
⭐ Battery powering a TS2068? 7 💬 2023-05-12 Michael A. Druckenmiller
⭐ TS2040 Thermal Printer Schematic 📎 7 💬 2023-07-12 Michael A. Druckenmiller
⭐ TS2068 Keyboard Membrane Conductive Strip 📎 6 💬 2014-06-26 Rich M
⭐ TS-1500 Schematic 📎 6 💬 2022-03-10 Carl Miles
⭐ TS2068 Internal Power Supply Replacement / Repair 6 💬 2021-09-02 Carl Miles
⭐ TS2068 Diagnostic Lab cartridge 📎 5 💬 2026-10-14 Jon
⭐ S-Video / Composite Video Color Fix.. 📎 5 💬 2019-04-18 rowokii
⭐ ts 1500 schematic 5 💬 2011-12-29 Billiam
⭐ Connect TS2068 to monitor 📎 5 💬 2025-08-01 Daniel Santos
⭐ "12-Volt Modification" [To Get a Clean Composite Picture] 5 💬 2008-01-07 Adam Trionfo
⭐ Sinistar arcade game cartridge port for the TS2068 ↳ #9979 4 💬 2026-10-13 David Anderson
⭐ A happy day! 4 💬 2021-05-21 exile_in_paradise
⭐ New Replacement Faceplates / Keyboard Overlays 4 💬 2019-02-14 Rich M
⭐ Diagnostic Cartridge for T/S 2068 4 💬 2022-10-14 Adam Trionfo
⭐ Starting the upgrade to Adam's TS2068 - Power Supply and AY Stereo Sound 📎 4 💬 2025-10-27 Carl Miles
⭐ My TS1000 3D Printed Case 4 💬 2022-09-10 Kevin Dorff
⭐ TS2068 with defective ROM ? 📎 4 💬 2022-04-12 François Lanciault
⭐ RAS/CAS timing from SCLD to lower RAM 📎 4 💬 2023-09-15 David Anderson
⭐ Horizontal bars display on power up, 📎 4 💬 2021-12-20 kirk
⭐ Defective 2068 3 💬 2026-05-27 David Laffineuse
⭐ TS1500 cost reduction version Diagram 📎 3 💬 2026-05-19 Joao Diogo Ramos
⭐ Dead Spider mod 3 💬 2026-04-17 Gus Lahoski
⭐ TS 2068 Schematic 3 💬 2024-05-30 David Anderson
⭐ Quick question on a ZX-80 3 💬 2025-07-24 Tim H
⭐ No video output on my 2068. 3 💬 2025-01-20 Christian Mann
⭐ Mahjongg ZX81+38 clone "NO DELETE" fix! 📎 2 💬 2024-10-04 RichJ
⭐ TS1500 composite video output 📎 2 💬 2023-03-20 Claudius
⭐ TIMEX TC2048 Schematics 2 💬 2005-03-09 displayhelp
⭐ Blown up TS2068 2 💬 2024-04-14 RichJ
⭐ Spider Mod for ZX Spectrum 48 Series 2 PCB 2 💬 2024-03-09 John Lech
⭐ 2068 power 2 💬 2025-09-29 RichJ
⭐ TS Pico and diagnostics ROM/DCK 📎 2 💬 2023-12-26 Ricardo Calcagno
⭐ update regarding ZX81+38 problems 1 💬 2024-10-09 RichJ
⭐ Sucessful replacement of AY-3-8912 with AY-3-8912A 1 💬 2023-04-26 Ricardo Calcagno
⭐ Bad L2 1 💬 2026-06-06 RichJ
⭐ No plus 5 volts 1 💬 2026-05-27 RichJ
⭐ Production improved 1 💬 2026-04-11 Gus Lahoski
⭐ PCB repair soldering/unsoldering techniques 1 💬 2024-02-10 RichJ
⭐ TS2068 repair vs. symptoms 1 💬 2023-12-29 RichJ
⭐ 15 volt PS for TS2068 1 💬 2022-05-04 David Anderson
⭐ Horizontal bars display on power up 1 💬 2021-12-20 Ricardo Calcagno
A sad day... 📎 21 💬 2021-11-03 Adam Trionfo
I am trying to setup a Sinclair ZX-80 and I need a little help 📎 20 💬 2023-02-27 John Mobley
To Christian Mann RE: TS2040 INK 18 💬 2025-02-02 Adam Trionfo
TS1000 keyboard repair options? 📎 16 💬 2022-09-12 Kevin Dorff
Timex 1500 LOAD"" issue 📎 15 💬 2023-08-18 chapas
Cambridge Z88 📎 14 💬 2024-10-12 Greg Skuza
Potential source for the TS2068 SCLD Chip? 📎 14 💬 2024-01-05 David Anderson
Well I finally added the Z88 to my collection... 📎 13 💬 2024-09-26 Carl Miles
Question about ntsc video output ↳ 12 💬 2005-03-06 Peter Z Lakatos
E-Z Keyboard Interface 📎 12 💬 2024-01-14 Richard Burt
TS Online User Group Meeting Monday June 2 ↳ #8312 12 💬 2025-07-18 David Anderson
help with 'dead' t/s 2068 11 💬 2003-11-21 Alvin
Easy question of the day and strange thoughts ↳ #8480 📎 11 💬 2025-09-19 Mark Scheck
Repairs 11 💬 2022-01-12 Richard Burt
Arrived: Timex Sinclair 2068 - with an issue 📎 10 💬 2024-10-05 Thomas Hynes
TS 2068 --> CGA monitor. No BRIGHT ? ↳ 10 💬 2008-04-18 M. Emrah Oral
ZX81 and TS1000 on Adrian’s Digital Basement 📎 10 💬 2025-04-07 Timothy Swenson
2068 video problem 📎 9 💬 2015-04-27 Bob Aviles
2068 Upgrades 📎 9 💬 2023-10-17 Willie Jones
This is just turning into a comedy of errors 8 💬 2024-10-07 Thomas Hynes
Still lookng for a power source 2068 📎 8 💬 2024-10-06 Thomas Hynes
Solder pad problem 8 💬 2008-01-11 Adam Trionfo
Compatible low profille keyboard for TS1000 keycaps? 📎 7 💬 2026-04-25 Michael Hart
ZX81 clone 📎 7 💬 2024-06-01 David Anderson
TS-1500 unknown port 📎 7 💬 2023-11-18 François Lanciault
A problem with the DK'TRONICS keyboard. 📎 7 💬 2025-05-19 Christian Mann
Technical Help Needed 7 💬 2007-05-17 Paulo Leite
TS1500 ↳ #178 6 💬 2021-07-01 toyer1
Timex 1000 Weird Motherboard Wire 📎 6 💬 2022-12-20 Adam Trionfo
Any ZX Spectrum boards? 📎 6 💬 2025-05-18 Christian Mann
Bad TS2068 6 💬 2025-04-28 Paul Holmgren
My 2068 and MC-10 6 💬 2025-04-28 Christian Mann
Memory chips 5 💬 2006-02-28 Senen Racki
ZX81 clone saga continues 📎 5 💬 2024-07-18 RichJ
TS 2068 Colors not displaying correctly 5 💬 2011-11-08 beanz991
Timex 2040 printer - schematic wanted 📎 5 💬 2022-08-23 Claudius
TS2040 printer power supply 5 💬 2023-09-23 Floppy Days Podcast - Ra
New labels for my DK'Tronics keyboard. 5 💬 2025-03-02 Christian Mann
TS2068 board - faulty unit needed 📎 5 💬 2023-07-30 Claudius
terribly fuzzy and black and white video.. 4 💬 2006-02-23 Stephen Wenzler
TS1000 Display Question 4 💬 2024-08-23 Carlos M. Nunez, M.D.
2068 IC kits from China? 4 💬 2024-08-06 Patrick Leclerc
Mystery Board 📎 4 💬 2026-03-17 Joe VandeZande
TS-Pico DIY Build Notes 4 💬 2023-12-22 Ricardo Calcagno
The bad, noisy, disreputable TS 2068 4 💬 2008-02-22 george.orr1
Need help with my TS2068 4 💬 2007-10-03 zxbruno
2068 repair help 📎 3 💬 2026-10-18 Retro Dreamstate via gro
Problem with power supply or TS2068 3 💬 2005-12-12 jfroco
Lots 📎 3 💬 2024-08-09 RichJ
Timex Sinclair 2020 replacement belts 3 💬 2024-07-21 Patrick Leclerc
Unstable TS2068. 3 💬 2005-08-16 Jarek Adamski
2068 power supply 3 💬 2012-07-19 Mark Scheck
Voltage converter in Timex FDD 3 3 💬 2004-10-29 Jarek Adamski
Keyboard connectors for ZX81/TS1000 3 💬 2025-10-21 T2
Display help! 3 💬 2010-05-12 mwilliwood
TC2048 rescued from old storage place 3 💬 2009-03-31 zxbruno
Diagnostic rom for the ts1000/zx81 3 💬 2025-05-27 John Mobley
TS 1500 faceplate 3 💬 2022-03-21 David Anderson
TS1000 Keyboard 3 💬 2022-03-12 Jimmy Ipock
TS2068 power supply 3 💬 2023-09-10 Floppy Days Podcast - Ra
2068 Key Board 📎 3 💬 2023-06-28 Willie Jones
ROM replacement on the 2068 3 💬 2007-05-29 Rod H
TS 2068 SPEAKER HELP 2 💬 2017-11-13 beanz991
Replacement for L2 2 💬 2026-06-08 David Laffineuse
Wow 📎 2 💬 2026-06-02 RichJ
TS2068 has sound but no beep 2 💬 2016-02-02 des.1950
Broken T/S 2068 repair tips request; extra PCB on mobo 📎 2 💬 2023-02-23 qwertyfan2000
TS2068 Power supply & Rom Switch 2 💬 2014-01-31 rjburt56
Spectrum board testing 2 💬 2026-04-02 Gus Lahoski
Just got a TS2068 -- but no video/TV output? 2 💬 2013-04-28 unbonnevie
Overload the Buss 2 💬 2012-09-19 pxx1_2000_32724
Larken Drive Cable issues (I think) 2 💬 2012-07-02 pxx1_2000_32724
dead ts2068 2 💬 2004-02-17 David
TS2068 Keyboard? 2 💬 2002-11-12 Pat Wisniewski
EZ-Key keyboard 2 💬 2022-06-08 David Anderson
TS2068 board repair 2 💬 2023-11-22 Ian Baronofsky
2068 SCLD 2 💬 2023-11-18 Floppy Days Podcast - Ra
Replace Voltage Regulator in 2068 with 78M12?‏ 2 💬 2008-01-06 Adam Trionfo
Strange Colors with my TS 2068 2 💬 2008-01-03 Adam Trionfo
TS 2068 - Sound/Hissing Problem 2 💬 2008-01-02 Adam Trionfo
2068 Power supply mod - Dave's U-Tube video 2 💬 2023-06-20 Willie Jones
Restoration of a TC-2048 2 💬 2021-07-13 David Anderson
Extra powersupply 1 💬 2006-11-27 Tony
TS2068 pico and video cards 1 💬 2026-10-14 RichJ
TS2068 in Need of Repair 1 💬 2005-09-14 Paulo Leite
A Monumental Breakthrough 1 💬 2026-04-03 Gus Lahoski
My trip to Dundee, Scotland 1 💬 2026-03-30 Gus Lahoski
Timex Motherboard 1 💬 2005-03-12 eric johnson
Power issue 1 💬 2025-09-28 David Laffineuse
Suntronics Full Size Keyboard Conversion 1 💬 2003-06-26 Louis Florit
How hot is your TS2068? 1 💬 2009-03-23 zxbruno
Lessons Learning From Soldering Mistakes 1 💬 2008-01-10 Adam Trionfo
TS 1500 keyboard mats 1 💬 2022-01-13 David Anderson
Replace Voltage Regulator in 2068 with 78M12? 1 💬 2008-01-06 Adam Trionfo
Strange Colors with my TS 2068‏ 1 💬 2008-01-04 Adam Trionfo
old hardware ↳ #6466 9 💬 2024-04-11 Paul Holmgren
1st Post Finally! 📎 4 💬 2024-11-06 peyton.bratton
dug out 'Treasures??' for the hardware types?? 📎 4 💬 2025-05-20 Paul Holmgren
TS1000 On The Way 3 💬 2023-10-20 JEFFREY L BURRELL
Okay 3rd time is a Power Supply 📎 2 💬 2024-10-06 Thomas Hynes
Bad 2068?! 2 💬 2026-06-02 RichJ
Wanted: T/S 2068 States and Capitals cartridge, 2068 pwr supply, educational sw 2 💬 2012-01-09 jon0x0
I know a couple of folks were looking for TS2068 cases a little while ago.. 2 💬 2022-03-02 Scott Hardin
Christian's flaky 2068 2 💬 2025-01-01 David Anderson
Great 1 💬 2026-05-27 RichJ
1000 board for the Motherboard list. 📎 1 💬 2025-05-18 Christian Mann
Replacement TS2068-- All Right! 1 💬 2008-02-02 Adam Trionfo
TS2020 for sale - needs repair 1 💬 2007-07-31 zxbruno
2 Timex Sinclair 2068s. For parts or to be repaired. 1 💬 2007-07-31 zxbruno