-
DIY Issue 1 Internal 32K RAM expansionFollowing on from the information in [URL="http://www.worldofspectrum.org/forums/showthread.php?t=40173"]this[/URL] thread, I finally figured this ou…
... a stripboard version of the Issue 1 internal RAM module.
Issue 1 board are available from ... by adding decoupling capacitors across power connections to the two chips ... -
Which ULA to fit in which issue SpectrumI spent a little while studying the resistor changes on page 30 of the ZX Spectrum 48K service manual. They all concern aspects of the video circuit …
... board.
All issue one boards are designed for ... best operation.
Issue 3 and 3B boards are designed for ... take anything earlier.
Issue two is the board with ... although this was made after Issue two ceased production. The quick ... -
Power connector for 48K SpectrumI need a new power connector for an Issue Two 48K Spectrum board, quite an early one. Where can these things be obtained? Someone must know! There mu…
I need a new power connector for an Issue Two 48K Spectrum board, quite an early one. Where can these things be obtained? Someone must know! There must have been a load of these sourced for Harlequin projects, and also for Spectrum fixes. -
Issue 4S differencesI decided to buy an Issue 4S PCB after reading much about them on here. It was originally in a plus case which didn't come in the sale. I've been run…
... s actually different about the Issue 4S. Is it closest ... to Issue 4A or Issue 4B? As a ... The 12V and -5V power supply is much quieter than ... problem is with using the Issue 4S with Divide. So ... isn't implemented properly on Issue 4S. Is this likely ... -
New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... an attempt to fix a issue 2 rubber key 48k I ... [/URL]
If you power it on and off sometimes ... -
Seriously weird Issue 2 issue... (RAM-related)Hi guys; I have been trying to fix up my Issue 2 and have run across a bizarre issue that I haven't seen elsewhere in the forums. Hopefully one of …
... to fix up my Issue 2 and have run ... across a bizarre issue that I haven't ... narrative:
Spectrum: Issue 2, 48k
Initial problem ... VR1,2 fixed the colour issue.
2. MEMCHK returned ... happens:
On power on, the Spectrum has black ... -
Issue 3 expansion connector problemI am having problems with an issue 3 Spectrum, that otherwise works fine, but does not recognize either the Interface 1 or DivMMC/Enjoy (which are bo…
... am having problems with an issue 3 Spectrum, that otherwise works ... />
This is not a power supply problem either, the +5 ... -
Video fault on issue two ZX boardI've trawled the Internet and drawn a few blanks as to where to look to resolve the fault with my issue two board. I'm hoping a few of you knowledgea…
... resolve the fault with my issue two board. I'm hoping ... working Spectrum 48k with a 3B board I've checked the ... -
Issue 3 ULA ProblemsI've been given an Issue 3 48k to fix. It was producing no video and no picture on the TV. The coil was buzzing so it was getting power and all the v…
I've been given an Issue 3 48k to fix. ... buzzing so it was getting power and all the voltages tested ... a spare ULA from an Issue 4(6C001E-7) which ... working keyboard and the same issue with none functioning keys was ... out of a known working Issue 4 and this time ... -
Faulty Issue 1Hi all, thought I'd document my efforts in getting another speccy working. I've never done this before so please bear with me... I recently took a p…
... one off of ebay ("missing power supply - unable to test" ... installed. Lo and behold - initial power on reveals duff 7805 and ... with a Traco Power DC-DC convertor. Power on and I ... worldofspectrum.org/forums/discussion/51557/issue-1-schematics#latest"]here[/url ... -
No colors on screen, issue 2.I have a 48k issue 2 with composite mod. When i first pluged it in after i bought it, the screen went yellow and after restart there were no colors a…
I have a 48k issue 2 with composite mod. When ... no success. Any ideas? The power suply is also replaced. -
Laptop issueMy laptop seems ti have died, i noticed yesterday when i switched it on there was no hard drive activity and the screen was blank, even though the po…
... was blank, even though the power light was on.
I ... if anyone knows what the issue could be, is it worth ... -
ZX Spectrum issue 4B acquiredI recently acquired a ZX Spectrum with serial number 138-363292 on the case, and a 1983 issue 4B board I got it for the purpose of repair. and have…
... the case, and a 1983 issue 4B board
I got ... />
I have yet to power is on but i was ... -
Issue 2 problem.Hi all, I'm trying to repair / upgrade an Issue 2 Spectrum for a friend, but have come accros the following problem. When I power the machine …
... trying to repair / upgrade an Issue 2 Spectrum for a friend ... problem.
When I power the machine on I get ... the odd thing, if I power up with the Sinclair test ... -
Replace Issue 2 speakerI was wondering as the speaker in an issue 2 speaker is 200 ohms, would swapping a 40 ohm later spectrum speaker in help with tape loading, less load…
... as the speaker in an issue 2 speaker is 200 ohms ... the circuitry to match what issue 3 schematic, which should make ... back so the spectrum can power it along with a kempston ... -
Issue with TV signal + Inductor Coil (16K Issue 2 Speccy)Hello guys, I just got a 16K Issue 2 Speccy from eBay. It was sold as not working so I knew there would be some work needed before it's working ag…
... /> I just got a 16K Issue 2 Speccy from eBay. It ... . Then however I noticed an issue with TV signal which normally ... basic measurements (this time with power on) and the only result ... two videos - one showing the issue with TV signal and another ... -
ZX Spectrum Issue 4S composite video fuzzy (horizontal blur)Dear people of WoS, Thank you very much for taking the time to read. I have an Issue 4S I recently acquired and planned to fix up as a gift for a…
... to read. I have an Issue 4S I recently acquired and ... a friend.
The issue:
Composite video out on ...
Checked comp side connector power voltages (noted discrepancy for 23 ... br /> Checked under side connector power voltages 4.92v (3), 8 ... -
Fixing a poorly Issue 3 - Odd faults.Here's one for you Spectrum fixers, I warn you it's a long one. I've spent a couple hours this evening doing several repairs on a rubber keyed Speccy…
... on a rubber keyed Speccy(issue 3) that I can't ... . First thing I did was power the Speccy up and connect ... -
48K Issue 2 RAM issuesI have 48K issue 2 board (I've checked, the upper memory is present!). It's not very well. I've not attempted to diagnose one before, so please bear …
I have 48K issue 2 board (I've checked, ... me.
If I power it up, I get colourful ... block pattern corruption. If I power it up with a DivMMC ... -
Help request for an injured Issue 4A spectrumHi folks, I'm hoping to resurrect an issue 4A spectrum that has been in my hoard for a couple of decades since buying it for spares. Someone ha…
... 'm hoping to resurrect an issue 4A spectrum that has been ... still hot happy with the power - it makes a slightly odd ... -
48k issue 4B display problem etchi,, i have a zx spectrum 48k issue 4B with a display issue it has wavy lines in both the border and paper,some colours seem worse than others ie red…
... zx spectrum 48k issue 4B with a display issue it has wavy ... few red lines. re applying power results in successful boot every ... composite mod with the same issue.. i have tried everything short ... -
Quirky nerdy hardware quiz time[b]Quirky nerdy hardware quiz time[/b] [list=1][*]How many transistors are on the issue one ZX Spectrum PCB? [color=#FFFFFF].[/color] [*]Which d…
... transistors are on the issue one ZX Spectrum PCB ... s special about the ZX81 issue two board?
[ ... [*]What’s the rated power output of a Sinclair UK1400 ... [*]What’s the normal power factor of an old style ... Spectrum +2A/+2B/+3/+3B computers can be configured ... -
Original Kempston interface on a +3Hello everyone, if i insert an original kempston interface in the extension port of a +3 should it work or not? I tried it and the machine didn't bo…
... that deamn amstrad placed the power supply connector too close the ... and some pin (in the power supply jack) doesn't ... is enough space for the power supply connector and the ... /> My +3's board has "issue two" written on it, does ... or not? Is this the +3B version? -
Original Kempston interface on a +3Hello everyone, if i insert an original kempston interface in the extension port of a +3 should it work or not? I tried it and the machine didn't bo…
... ;deamn amstrad placed the power supply connector too close the ... pin (in >the power supply jack) doesn't ... ;enough space for the power supply connector and the ... +3's board has "issue two" written on it, ... not? >Is this the +3B version?[/QUOTE]
... -
Flicker fixer for ZX 48KHas anyone the schematics for the flicker fixer: [URL]http://8bit.yarek.pl/computer/zx.48/[/URL] Micky
... /> Pictures belong to a 4B issue board, but this will do ... /3B. Not sure if the traces are the same place in issue ... work OK with a 4A issue board and a SGS brand ... a piece of wire and power on. If it boots, ... actual mod tested on a issue 4A board.
[ ... -
Spectrum +3, Issue 2...I have just had plonked on my desk a nice issue 2 Spectrum +3. I'm not sure if its 100% working yet, as I have not plumbed it into a telly. So, assu…
... on my desk a nice issue 2 Spectrum +3. I ... board says it's an issue 2. Does this need ... that the "3b" is fine, is this the issue 2 +3 ... ?[/QUOTE]
Both Issue 1 an Issue 2 motherboards have the ... leaks interference onto all the power and ground lines.
... -
Datasheets of the Spectrum 128K +2 ICs.Is there any place where I can find the datasheets of the ICs of the Spectrum 128K +2? I have tried to look for each of them separately but for some…
... the relevant model and PCB issue number.
For information ... has the "barrel" type DC power connector) is a development of ... DIN connector for the DC power inputs) and +3 machines.
3B are [url="http://zxnet.co ... -
Spectrum 128k 2a or not 2b....Just picked up a +2 black case version and I'm in as little bit of a quagmire, The case is definitely black, has '+2A' stamped on the bottom, but in…
... fitted modification to the Z70833 ISSUE 1 board, this was incorporated ... the PCB on the ISSUE 2 and ISSUE 4.
Other ... the blanking modified, 2b and 3b are already done to approx ... line, plus until my atx power supply turns up I can ... -
New video about S-video modification on Issue two 48K Spectrum.I just finished an s-video modification on an Issue two 48K Spectrum so I made a video about it. Most of the technical details are in the video; if y…
... noisy display when compared to issue 2.
I am ... -video modded spectrums (board issues 3B and 4S) and none looks ... change to a regulated/filtered power supply.
Sorry, I ... viewing computer displays but your issue 2 isn't looking all ... -
+3 - beeper sounds but no AY musicHi guys I am repairing a plus 3 revision 2 board that had no sound at all. Using schematics from https://zxnet.co.uk/spectrum/schematics/ I manage…
... so supplies the circuit with power. As capacitors are not perfect ... a +2A, +2B, +3 or +3B, the voltage regulators are in ... Spectrum...
Further, the power network will transmit any electrical ... test.
The only issue I have is that I ...
