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The Spectrum Resuscitation ThreadKicking off this thread as a place where people who are fixing/restoring Spectrums (or indeed any other piece of related hardware) can show off their…
... also installed but I've not tested saving or loading yet ... , we have 48K of working RAM:
[IMG]https://farm8.staticflickr ... of my diagnostics, which assumes lower RAM is good and just tests ... -
TR4/TR5 replacementHi guys, I've got another Spectrum I'm working on now - an Issue 4S this time. When I originally got it, I powered it up and did the basic tests a…
... removing all the lower RAM IC's (they're not socketed so I ... -
TR4/TR5 replacementHi guys, I've got another Spectrum I'm working on now - an Issue 4S this time. When I originally got it, I powered it up and did the basic tests a…
... Ben V to replace the lower RAM ICs. All of the currently ... an electronics background and am not massively experienced. I can only ... -
You get what you pay for-You live and learnDecided to try for a cheap spectrum + on ebay described as not being able to tune it and some keys did not work - haha Duly received and opened up a…
... , could this point to the lower ram ?, voltages seem to be showing ... on the regulator and lower ram.
Not even looking at using ... -
You get what you pay for-You live and learnDecided to try for a cheap spectrum + on ebay described as not being able to tune it and some keys did not work - haha Duly received and opened up a…
... /> It is most likely a lower RAM fault, but if the border ... screen ( Analogue TV ) but could not tune it any better than ... .04 V
[B]LOWER RAM[/B]
O V - 0 ... -
ZX Spectrum issue 6a - yellow border problem<p>Hello!</p><p>I have problem with my Sinclair ZX Spectrum issue 6A, 48K. </p><p>I have changed low memory (all 4116 IC's) and coil, all electrolyti…
... , 9.9v with ICs.Without lower RAM, picture is http://solair.eunet ... /error01.JPG
and with lower RAM, picture is http://solair.eunet ... , when lower RAM is present. When I press reset when lower RAM is not present ... -
not working issue 3Hi all, I received this mobo from ebay, after start i have this on screen [img]http://forest.no-ip.org/wos/issue3_01/20150728_135908.jpg[/img] …
... or missing lower RAM and that's not surprising given the RAM's power ... supply voltages presented to the lower RAM ICs, it's quite likely ... 's quite possible a failed lower RAM IC or a dead electrolytic ... to remove all of the lower RAM ICs as it's very ... -
not working issue 3Hi all, I received this mobo from ebay, after start i have this on screen [img]http://forest.no-ip.org/wos/issue3_01/20150728_135908.jpg[/img] …
... :( for me lower ram is fine.
I think digiboard not working on ... etc. digiboard don't pass lower ram on this machine ....
[img ... different working with no result, lower ram chips come from working speccy ... -
not working issue 3Hi all, I received this mobo from ebay, after start i have this on screen [img]http://forest.no-ip.org/wos/issue3_01/20150728_135908.jpg[/img] …
... to the middle of the lower RAM testing code. Since the IX ... bits in lower RAM), the code then thinks that some lower RAM IC's ... if you're interested in seeing what the tests do :)
Dead SpectrumHello guys, I've just bought a dead Speccy 48k (Rubber Keyboard Issue 3 board). Basically, when powered on it initially appears to boot up ok, but in…
... . If the copyright screen does not come up, either the connection ... is not good, or the problem is one of the lower RAM (4116 ... correct chip, and be careful not to slip and short anything ...Dead SpectrumHello guys, I've just bought a dead Speccy 48k (Rubber Keyboard Issue 3 board). Basically, when powered on it initially appears to boot up ok, but in…
I would buy a lower RAM module first. The 4116 ... chips used for the upper RAM.
To ... that does not need [i]any[/i] working RAM) running from ... Note that these devices are not listed in any order, and ... I have tried some, but not all.***
...Dead SpectrumHello guys, I've just bought a dead Speccy 48k (Rubber Keyboard Issue 3 board). Basically, when powered on it initially appears to boot up ok, but in…
... say that inhibiting the upper RAM's /CAS signal ( ... always prevent faulty upper RAM from interfering with the ... almost as common as lower RAM ones, so I wouldn ... is in the upper RAM; the lower RAM is able to receive ... the fault, it might not even be possible to run ...ZX Spectrum issue 2 has only blue tintsRecently I've bought a 16k speccy and ran into some issues with it. Faulty keyboard, broken caps, no stable frequency, faulty lower RAM chip, it bein…
... not safe to run the machine further as damage to the lower RAM ...48k not startingHi team, I have 2 48k's, one works (Issue 4s), one doesn't (Issue 4a). The non-working one appears to start, but not finish the RAM test. The pape…
So... assuming the ULA is not the cause (that is you ... /> [*]Hard way #2 - remove one lower (4116) DRAM chip at a ... with good ones, or a lower RAM module.
[*]Less hard way ...48k not startingHi team, I have 2 48k's, one works (Issue 4s), one doesn't (Issue 4a). The non-working one appears to start, but not finish the RAM test. The pape…
... "]So... assuming the ULA is not the cause (that is you ... /> [*]Hard way #2 - remove one lower (4116) DRAM chip at a ... with good ones, or a lower RAM module.
[*]Less hard way ...Spectrum CapacitorsLooking for some opinions here, if I may? In the 80's and 90's I used to repair Spectrums and other machines for a living so I'm reasonably famili…
I tend not to like replacing anything that ... and often lead to the lower RAM being damaged. Those in the ... and that can damage the lower RAM too.64k speccydoes anyone have instructions on how to use the extra 16k found in some spectrums?
... bit chips, but did not pass the semiconductor manufacturers quality ... partly working chips. I have not bothered investigating this.
... bytes comes from 16k bytes "lower" RAM plus two banks of 32k ... ) of "upper" RAM. If the board does not have fully working ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... 8 of all of the lower RAM, which if done such that ... you're not confident, best to snip all the lower RAM out - new ... cheap, and if you're not bothered by originality, one of ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... aiming for........but all is not lost. I do believe great ... the thought of Zorn's lower ram replacement got ever more appealing ... off the rest of the lower ram IC's, their legs are ... thinking that to buy the lower ram replacement module is the next ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... was going on underneath every lower ram IC, I uncovered nothing, but ... donor board with 4116's, not very good at removing chips ... 'll probably go for the lower ram replacement module or buy a ...Issue 1 schematics?I'm fault-finding an issue 1 board. So far I've found a hot memory chip and snipped it's supply legs, then swapped the burnt-out 7805 for a switched…
... important tip is that the lower RAM IC's are in a ... />
I seem to recall seeing an Issue 1 schematic somewhere ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
OK could not wait for Sunday. Half ... here.
Placed a lower ram module carefully into the sockets ... and the machine does not to react when I press ... today since putting in the lower ram, after running the board ... with the work on the ram replacement, but we can ...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…
... seller of the most common lower RAM replacement module ( http:/zx.zigg ... a suspicion that it might not work in an issue 1 ... you need to replace the lower RAM in this Spectrum, please contact ...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…
... need to put some good lower RAM in? If so, I could ... 's 16k RAM chips are fine, so I have not had a ... devices) use a ROM based RAM tester (yes, I know the ... has run, remove the 16k RAM chips by cutting all the ... it works, job done. If not (and you are using DRAM ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... this time with the replacement lower ram module removed.
[url]https ... been replaced, but I did not advise on the transistor itself ... with that since I do not have the tools to program ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
Hmm.
All is not good.
I moved the ... suspect I have a dodgy lower ram module, or there's something ...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…
... if I ordered a lower RAM module he'd send ... some info on how his lower RAM performed.
... />
Zorn's Ram module plugged straight in and ... speccy? (8K ROM, 8K RAM?) The manual didn't ... />
Zorn - I've not forgotten my pledge. What do ...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…
... "]Zorn - I've not forgotten my pledge. What do ... , /CAS, /WE) on the lower RAM end. But I'm unsure ... different (!) ULA versions it's not afaik.
There ... check though: (with that RAM replacement module inserted)
... ULA reads from the lower RAM.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…
... a report of problems with lower RAM before and as the ULA ... and not when someone tried using a SRAM to replace the lower RAM ...
