Spectrum 128 +2 grey RAM fault

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Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Spectrum 128 +2 grey RAM fault

Post by Lardo Boffin »

Hello all

I just taken delivery of a bit of a battered +2 which clearly has a RAM fault! This from the B.Alford diagnostics:

5ED454D5-D439-471E-A849-7BDFD1621ACB.jpeg

It looks like it has had a bit of a hard life judging by the RF modulator (and scratches, lack of feet etc.)…

2BD58E76-7C01-4E62-82D9-824FF4C781C4.jpeg

Any idea which chip this is referring to? Is it the lower RAM?

Thanks!
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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1024MAK
Posts: 5101
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Spectrum 128 +2 grey RAM fault

Post by 1024MAK »

Yes, but I need to check before I commit.

<Pedantic mode>The 128K machines don’t technically have ‘lower’ RAM chips as such.</Pedantic mode>.
I normally call the two banks ULA RAM and Z80 RAM.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: Spectrum 128 +2 grey RAM fault

Post by Lardo Boffin »

Thanks! I kind of didn’t think it was lower RAM on a 128 but had no idea what to call it!
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
User avatar
Tiger
Posts: 88
Joined: Tue Sep 01, 2020 10:37 am

Re: Spectrum 128 +2 grey RAM fault

Post by Tiger »

Data line 0 is IC32 on the +2 board ...
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: Spectrum 128 +2 grey RAM fault

Post by Lardo Boffin »

Thanks! Will be ordering a few RAM chips shortly.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: Spectrum 128 +2 grey RAM fault

Post by Lardo Boffin »

IC32 changed and yay!

E93BBD3D-F76C-4666-BC36-7D23DF928AFC.jpeg
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
User avatar
1024MAK
Posts: 5101
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Spectrum 128 +2 grey RAM fault

Post by 1024MAK »

8-)

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: Spectrum 128 +2 grey RAM fault

Post by Lardo Boffin »

It is also now has feet and is a lot cleaner. Tape belts on the way.

BDCE2163-2395-485D-BBCB-5639D80D0ACD.jpeg

I would described it as a +2 green rather than grey given the sun damage. Next to a grey filing cabinet for reference.

002F668F-E70A-4675-A9E2-D49EBFDEBB99.jpeg
Last edited by Lardo Boffin on Thu Jan 26, 2023 3:25 pm, edited 2 times in total.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: Spectrum 128 +2 grey RAM fault

Post by Lardo Boffin »

Thanks to helping my son with his new found Warhammer interest I am getting better at painting small things!

Before:
6CC9C120-3E5D-4D56-86BC-9576E2055756.jpeg
First coat:
CE6F1ADB-02D2-44AD-A354-30B85EADEB26.jpeg
Second coat:
13C85CC7-74C8-45EE-83D2-4FB16A491F92.jpeg
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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