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The Complete List Of The Causes Of Lower Ram Failure?Well the aim is to get a comprehensive list.I ask this because I know very little about it . I know that failure of "power supply" related capacitors…
Well the aim is to get a comprehensive list.I ask this because I know very little about it . I know that failure of "power supply" related capacitors can do this . But I suspect there are loads of other ways to damage lower RAM ICs? Any ideas? -
ZX Spectrum 48k Issue 2 Faulty Ram?Hi, I have a faulty ZX Spectrum Issue 2 motherboard. Looks in very tidy condition. Though I'm getting random columns of blocks and flashing cursors…
... read would indicate a lower ram failure. I have lightly touched the ... seem cool.
The ram fitted is 8322 4116 2N ... -
Black screen on 48k+Hello peeps Just bought a 48k+ was working fine then after leaving it off over night I turned back on to get a total black screen, no border etc. …
... seems to be an upper ram failure. ICs 15-22 apparently each ... easier way of finding which ram chip is responsible? Also. How ... -
What are the chances?Hi all, I've picked up an issue 3B, fairly clean board, no mods, wasn't starting correctly so I tried Brendan's diagnostic ROM and got this: [i…
... [/img]
Total lower RAM failure? Before I start pulling all ... the RAM out, is it possible that ... -
bizarre error on a grey ZX Spectrum+2 - the long search for a small problemHi, I got a ZX Spectrum+2 that worked a bit but crashed while loading or running 128k games. I installed a 128k-test-ROM that told me about RAM fa…
... -ROM that told me about RAM failure at page 3. I desoldered ... 8 RAM chips that included page 3 as the failure seems ... to be located in several RAM cells not ... I removed the second 8 RAM chips - to save time I ... -
OT: Graphic Card problemAhem. It's me again with a computer problem! Last time I posted with a problem I was pleasantly suprised with some insightful answers that helped fix…
... card and said that the RAM was surely broken, these lines ... typical symptoms of a video RAM failure; so they gave me a ... -
OT: Graphic Card problemAhem. It's me again with a computer problem! Last time I posted with a problem I was pleasantly suprised with some insightful answers that helped fix…
... is using shared system/graphics RAM, you could easily get all ... problems, including duff boot screens. Intermittent RAM is a real pain to ... wrong. Did you change your RAM stick (assuming the card uses ... -
Speccy MTBFHi, Looking at the old (issue 1-2) PCBs, they do look like someone knocked them up in an etching bath/with a soldering iron in their shed but has th…
... because of triple power. With RAM failure usually voltage converter transistor died ... frequent. Then: CPU, ULA, 32KB RAM chips, modulator, power supply...
Poorly Spectrum + Fault diagnosis help needed!Hi, I've got a Spectrum+. Sometime in the past I broke it and sent it off to be fixed. It came back working good as new, but with an issue 2 board i…
Incidentally, why upper RAM can cause you non-initialization- ... simple, and can miss many RAM failure modes - therefore, to the ROM ... routine the whole of RAM checks out OK...but isn ...R.I.P. spectrum 48kRecently one of my 48k rubber key (issue 4) machine bit the dust the other day when I tried to power it on. When powering it on, it gave a weird 'bee…
... / Ohms...would this cause the failure? It did work flawlessly until ... suggest it's a lower RAM failure, but it could be the ...zx spectrum ULAis the ULA in the 16K the same as in the 48K could you take the 16K ULA and place it in a 48K I ask this because i have a speccy thats dogy with th…
Without the ULA you'll see nothing, because it generates the video. If you see the black rectangle with red lines, at least partially, it means the CPU starts and trying to perform RAM test. For me, it looks more like RAM failure.Spectrum 48k boots but small black dots start appearingAnyone any ideas where I should look first?
... ULA or the start of ram failure.zx spectrum 48k loading issue (memory problem i think)Hi I have a 48k spectrum that until yesterday was working flawlessly. The spectrum seems to work fine but the problem is with loading games.All the …
... above. Perhaps there's an intermittent RAM fault that only occurs when ... />
2nd option: run some RAM-test programs to test the ... RAM more extensively than the built- ...zx spectrum 48k loading issue (memory problem i think)Hi I have a 48k spectrum that until yesterday was working flawlessly. The spectrum seems to work fine but the problem is with loading games.All the …
... above. Perhaps there's an intermittent RAM fault that only occurs when ... />
2nd option: run some RAM-test programs to test the ... RAM more extensively than the built- ...Repairing a faulty 48K issue 2.I am investigating one of a pair of non-working issue 2 48K Spectrums that have been sitting in a cupboard untouched for quite a few years. I haven…
... br />
Removing the lower RAM was time consuming and fiddly ... almost certain is a lower RAM failure (it only sometimes fully initialises ... mechanism for refreshing the upper RAM while the ULA has ... the Spectrum with the lower RAM removed, it does sometimes ...RFC: Hardware Documentation ProjectI've noticed quite a few threads recently about missing schematics and suchlike. I've also been thinking about the low quality of some of the schemat…
... mode to help finding a RAM failure in non-contended area
RAM were damaged:
[url]http ... memory to help diagnosing intermitent RAM failures:
[url]http://www ...Spectrum 128K +2 problemhello, i am try to repair my spectrum 128k +2 grey, i remove all ram chips and i have some new ones spares, now i have remove all ram chips, i want …
RAM failure is the most likely (but there are some other possible causes).
This last picture does indicate that the ULA is working.
[I][B]Mark[/B][/I]Faulty 48K Issue 3 motherboardHi I have a faulty Issue 3 motherboard and would appreciate it if somebody can steer me in the right direction of where to begin with the fault find…
... /> how did you check the RAM ic's ULA, CPU and ... , etc. as with a lower RAM failure.
I tested the ... RAM IC's, ULA, CPU and ...Poorly Issue One 16k spectrum diagnosis?Hello, everyone. :smile: I was lucky enough to buy an Issue One 16k rubber key the other week; I didn't know it was an Issue One till I opened it up…
A RAM failure is the most likely cause. ... power supplies to the 4116 RAM chips (+5V, +12V and - ... are not correct, the 4116 RAM chips will not work correctly ... ROM that will test the RAM and tell you what bits ... of the RAM are faulty.
[ ...First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... typical pattern of a lower RAM failure any more.
I ... most likely in the upper RAM area.
You could ...First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... typical pattern of a lower RAM failure any more.
I ... most likely in the upper RAM area.
You could ...Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... times) to indicate the lower ram failure
- After that all LEDs ... me this means that all RAM chips are faulty which is ... and all upper Ram chips
128K Ram test ROM
Very odd problemHmm, loaded up Sanxion on another 48k+ I have here only to find that when it had loaded there were no enemies on screen, furthermore on loading Atic …
... could be quite a localised failure in that IC as the ... specific (and benign for a RAM failure), and would seem to rule ... out a multiplexer failure also?
BHelp! +3Just got my +3 working after replacing the drive belt. All was OK until I plugged in my Multiface 3 (known working with a +2a) and the computer went…
... steady green border indicates a RAM failure.
However the IC ... (Memory IC's are 4464 RAM, IC3-6).
Either ... way, if the RAM is socketed, grab a couple ...Spectrum Not Responding to Keyboard InputHello, sorry if this thread is not in the correct place, This is my first post and I'm not sure where to post this type of thread. :lol: Anyway, I r…
... would indicate a possible lower RAM failure (8 chips at the bottom ... the board), the latter a failure either in the CPU, or ... in the lower/upper RAM that is holding a data ... like the above when upper RAM is not behaving itself (machine ...Spectrum Not Responding to Keyboard InputHello, sorry if this thread is not in the correct place, This is my first post and I'm not sure where to post this type of thread. :lol: Anyway, I r…
... narrow this down to a RAM failure of some sort.
RAM from the system to narrow ...Spectrum Not Responding to Keyboard InputHello, sorry if this thread is not in the correct place, This is my first post and I'm not sure where to post this type of thread. :lol: Anyway, I r…
... narrow this down to a RAM failure of some sort.
RAM from the system to narrow ... of this, except the "upper" RAM chips are disabled, not isolated ... being pedantic? Well, sometimes a RAM chip goes faulty in such ...48k black paper white borderI recently sold a speccy to a guy, unfortunately the power supply didnt survive the trip, so on replacing for him it seems neither did the speccy! H…
... see it causing a lower RAM failure as there wouldn't be ... causes knock on effects to RAM voltages etc.
I ... day then suffer an upper RAM failure!
BSpectrum Plus display issueHi, does anyone know if this is fixable at all by someone with no experience? From looking on a similar post on World of Spectrum forum they mention…
... least one lower RAM chip are faulty here (a failure of one ... further guess is that the RAM failure is interfering with the data ...
