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16k spectrum crash?Hi, I have just been given a spectrum 16k. I plugged it in and it worked, but after turning the machine off and connecting the 32k (cheetah) memory …
... likely is part of the lower ram has packed in - either 4116 ... for the lower 16k, and this can fail when the ram packs ... -
Broken ZX Spectrum + (48k)Hi! I just got a ZX Spectrum + from a friend. He said it was working around 8 years ago when he put it into the cellar. It was in great condition - …
... .
upper/lower RAM faults are far more common ... problems often occur together (well, lower RAM & -5v anyway, for ... reasons)
the lower ram can often *almost* work with ... an 'almost boot' - genuine lower RAM faults generally give rise to ... -
Ecstasy & AgonyWhile checking out the area around Chennai Central station on Sunday, I came across this crowded narrow road taken up entirely by roadside vendors se…
... -5v supply to the 4116 lower RAM ICs is faulty, or one ... of the lower RAM IC's themselves - I've ... -
Want a Speccy Repaired?Maybe it's time to put my 'skills' to use.... Now that I've sourced some of the nastier transistors, I've fixed about 6 rubber keyed Speccys in the …
... yes I can. :) Probably the lower RAM has lost its -5V and ... -
broken ZX SpectrumHi there I was given a dead ZX Spectrum years ago, and being bored today thought I'd try it again. Its a Sinclair ZX Spectrum with lovely rubbery key…
... you say, it's probably lower RAM and/or Z80 but could ... -
broken ZX SpectrumHi there I was given a dead ZX Spectrum years ago, and being bored today thought I'd try it again. Its a Sinclair ZX Spectrum with lovely rubbery key…
... to be the Z80, the lower RAM block, the power converter that ... supplies the lower memory block, the ULA - in ... -
Nooooo my speccy died!??!!Hi! I am quite sad. :( Tonight I got a kempston interface so I rushed home to try it on my spectrum+ The edge connector of the interface was narrower…
... likelyhood as:
4116 lower RAM block 90% likely
4164 ... upper RAM block 50% likely
Z80 ... voltages needed to run the lower RAM, then the PSU section is ... .
Then check upper RAM, then the Z80 and then ... -
48k one dead, one dodgyhello everyone. I have 2 48k spectrum +'s (the one with the QL case). Both boards have issue 3B on them near the speaker. The first will power up …
... the board? Especially under the lower RAM chips? -
Black paper, white border. Ram fault?We have a speccy that wont work properly. When we power it up, we get white border around a black screen. We swapped the rom and ula with a working o…
... could be the Z80, lower RAM or upper RAM.
The best ... the voltages on the 4116 RAM first because you can immediately ... -
Spectrum Issue two problemI managed to bring back to life a issue two spectrum (at least the power supply cirquit). The screen is now crystal clear (after replacing all the el…
... a couple more things than RAM, but if the machine ...
I'd try the lower 16KB bank, as it's ... down, then you have bad lower RAM.
I had ... I thought it was a lower-bank chip (since the ... that someone replaced the lower eight 16Kx1 RAM chips with a ... -
Opus Discovery and +2A?Can anyone tell me if the Opus Discovery is compatible with the +2A. I've just bought a +2A off Ebay and couldn't find any info on compatability. If…
... to kill it, or the RAM/flash ROM and various other ... , the ULA and some of lower RAM just for good measure. -
Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... of the old-style RAM and replace them with ... effects achieved by lack of RAM refresh will be lost ... DRAMs?): You get the RAM chip count reduced 4 or ... 8 times. Old RAM drains lotsa power.
... longer be needed by the RAM replacement?
There ... -
Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... longer be needed by the RAM replacement?
[/QUOTE]
12 ... -
Dead Spectrum +Hi all, I've recently dug out my old Spectrum + with the idea of repairing it. When I last looked at it, when I was much younger, I was soldering a …
... voltages required to run the RAM. +/- 5V and +12V. ...
test and replace lower RAM. The RAM can be sort of tested ... /> test and replace the upper RAM. Same procedure - remove, socket, ... replace with known good RAM, test removed RAM.
Test ... -
toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... voltages required to run the RAM. +/- 5V and +12V. If ... />
test and replace lower RAM. The RAM can be sort of tested ... /> test and replace the upper RAM. Same procedure - remove, socket, ... replace with known good RAM, test removed RAM.
Test ... -
toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... and GND to the 4116 RAM with the +12/-5v supplies ... is likely to fry your lower RAM! Hideous devices, these 4116s...not ... can be replaced with static RAM! -
toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... and GND to the 4116 RAM with the +12/-5v supplies ... is likely to fry your lower RAM! Hideous devices, these 4116s...not ... ][LIST]
[*]Power supplies: Ok, lower RAM might fry with my *bright ... way to go. Especially with lower RAM, some video effect might be ... -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
... fix, you just change the lower RAM and it bursts into life ... one you change all the RAM and the CPU turns out ... . Won't take a 32K RAM expansion and everything on that ... -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
... as if there is bad lower RAM or TR3, ZTX313 is ... down. The RAM is working fine, and the ... Research Ltd, but only lower 16K only working. Ramtop ... computer can see all the RAM above 32768 - it just ... in every location in upper RAM - so it's half ... -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
... as if there is bad lower RAM or TR3, ZTX313 is ... Research Ltd, but only lower 16K only working. Ramtop ... lower 16K, so it all points to speed (AKA RAM ... reading does not know, RAM access time is usually ... stamped right after the RAM part number, generally after ... -
Problem with my speccy 48+My machine boots up but apon booting it freezes and you can see feint grey horizontal 1 pixel lines going down the screen. Is this fixable at all?
I think it'll be lower RAM. Those liines you see on ... message if there is enough RAM, but if PRAMT (Physical RAMTop ... the machine stack in screen RAM. Shouldn't be grey though ... -
On a 48K issue 6A......how can i isolate the 32K block? I want to test if there is any fault on the 4116's , leaving the 4532's out of the equation. Will removing the …
Also test the power supply transistors! Do you have the voltages to run the lower RAM?
Test TR3, that'll make the lower RAM appear dodgy if it's gone.
Test IC28 74LS04 too. -
On a 48K issue 6A......how can i isolate the 32K block? I want to test if there is any fault on the 4116's , leaving the 4532's out of the equation. Will removing the …
... garbage that's in lower memory, indicating that lower memory isn't ... the voltages are right on lower RAM, the 4116s are not single ... -
On a 48K issue 6A......how can i isolate the 32K block? I want to test if there is any fault on the 4116's , leaving the 4532's out of the equation. Will removing the …
... the lower RAM?
Test TR3, that'll make the lower RAM appear ... too.[/QUOTE]
The lower ram voltages are fine and i ... power supply.[/QUOTE]
Lower mem voltages:
Pin ... -
On a 48K issue 6A......how can i isolate the 32K block? I want to test if there is any fault on the 4116's , leaving the 4532's out of the equation. Will removing the …
... for each pin of each ram ic to rom, logic, ula ... case something was interfering with lower ram but still... nothing. No broken ... -
Spectrum 48K ROMHi Can anybody help I have an Issue 6a Circuit Board which has a faulty ROM Chip. Is it possible to program a ROM Chip with the 48K ROM and fit it as…
... seems related to
a) RAM refresh
b) ULA bus ... linked to same line in lower RAM.
In R is linked ... is linked directly to the RAM, and RASL in the ULA ... of the schematic do the RAM refresh, but I'm no ... -
Spectrum 48K ROMHi Can anybody help I have an Issue 6a Circuit Board which has a faulty ROM Chip. Is it possible to program a ROM Chip with the 48K ROM and fit it as…
Cheers
I had not spotted that, would it be to enable a wider selection of lower RAM chips used ? -
Problem with my speccy 48+My machine boots up but apon booting it freezes and you can see feint grey horizontal 1 pixel lines going down the screen. Is this fixable at all?
... most likely cause is failed lower RAM. However, since it's easy ... -
RGB OutputWas there ever a device available for the 48 that had a RGB output ? As an alternative , what about using a pc monitor (iirc these have seperate syn…
... 'm thinking of making a RAM replacement board with modern SRAM for ...
