Blue tint video issue
Blue tint video issue
After receiving my first Sinclair Spectrum 128 +2, I was overjoyed to see it was operating normally. Unfortunately, a few weeks later it’s producing this blue-tinted output:
I’d greatly appreciate any ideas you may have as to solving this issue. My system was tested blue with multiple NTSC/US LCD monitors via this SCART cable and SCART-HDMI box:
EDIT: The motherboard indicates "Z70833, 1988, Issue 2" which I suppose means model +2B. The boot screen reads, "128 +2A." The unit is Black.
I’d greatly appreciate any ideas you may have as to solving this issue. My system was tested blue with multiple NTSC/US LCD monitors via this SCART cable and SCART-HDMI box:
EDIT: The motherboard indicates "Z70833, 1988, Issue 2" which I suppose means model +2B. The boot screen reads, "128 +2A." The unit is Black.
Last edited by Airshack on Sat Feb 27, 2021 2:13 am, edited 1 time in total.
Re: Blue tint video issue
EDIT: This cable is labelled for the +2A, +2B and +3 models, version 2.3. It was working fine on my +2 the first few times I used it. This was the cable I received with the unit. I'm new to the Spectrum so I know very little.
Last edited by Airshack on Sat Feb 27, 2021 2:16 am, edited 2 times in total.
- 1024MAK
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- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Blue tint video issue
Okay, before you get carried away...
There are officially only two models of the +2, but as it’s Amstrad, it’s a bit more complex...
So, what is the colour of the case? Black or dark grey?
Does it use a 9V power supply unit (PSU) fitted with barrel power plug or a power supply that outputs +5V, +12V and -12V fitted with a DIN plug?
A +2 in a grey case with a 9V PSU fitted with barrel power plug is known as a +2 (grey). These need a 128K / +2 SCART cable. E.g, like this one: Sinclair ZX Spectrum+ 128K & +2 (Grey Model) RGB Scart Lead.
A +2 in a black case with a PSU that outputs +5V, +12V and -12V fitted with a DIN plug is either a +2A or a +2B (see the bottom of the case). These need a +2A / +2B / +3 SCART cable. E.g, like this one: Sinclair ZX Spectrum +3, +2A, +2B High Quality RGB Scart Lead.
Other sellers of suitable video cables are available. The above are just examples.
Mark
There are officially only two models of the +2, but as it’s Amstrad, it’s a bit more complex...
So, what is the colour of the case? Black or dark grey?
Does it use a 9V power supply unit (PSU) fitted with barrel power plug or a power supply that outputs +5V, +12V and -12V fitted with a DIN plug?
A +2 in a grey case with a 9V PSU fitted with barrel power plug is known as a +2 (grey). These need a 128K / +2 SCART cable. E.g, like this one: Sinclair ZX Spectrum+ 128K & +2 (Grey Model) RGB Scart Lead.
A +2 in a black case with a PSU that outputs +5V, +12V and -12V fitted with a DIN plug is either a +2A or a +2B (see the bottom of the case). These need a +2A / +2B / +3 SCART cable. E.g, like this one: Sinclair ZX Spectrum +3, +2A, +2B High Quality RGB Scart Lead.
Other sellers of suitable video cables are available. The above are just examples.
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.
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.
Re: Blue tint video issue
After opening the computer up and doing a little research it appears I have a BLACK +2B model due to the motherboard reading: Z70833, 1988 Issue 2.
Source may be dubious since boot screen indicates +2A.
Source may be dubious since boot screen indicates +2A.
Last edited by Airshack on Sat Feb 27, 2021 2:17 am, edited 1 time in total.
Re: Blue tint video issue
Now the unit is producing video which is yellow-ish and keeps switching on and off, cutting in and out. Perhaps I need to perform the RGB SCART blanking signal mod?
It appears I am using the proper RGB-to-SCART cable as I have the +2A or +2B model.
The most strange portion of this mystery is everything was working fine a few weeks ago with the same components:
Maybe the SCART-to-HDMI unit failed?
All guesses accepted and appreciated.
It appears I am using the proper RGB-to-SCART cable as I have the +2A or +2B model.
The most strange portion of this mystery is everything was working fine a few weeks ago with the same components:
Maybe the SCART-to-HDMI unit failed?
All guesses accepted and appreciated.
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Blue tint video issue
Both the +2A and the +2B report “+2A” on screen because they can use the same ROM chips.
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.
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.
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Blue tint video issue
Sounds like the function switching inputs on your HDMI box are detecting what they consider to be a marginal voltage level. Hence the erratic symptoms.Airshack wrote: ↑Sat Feb 27, 2021 2:01 am Now the unit is producing video which is yellow-ish and keeps switching on and off, cutting in and out. Perhaps I need to perform the RGB SCART blanking signal mod?
It appears I am using the proper RGB-to-SCART cable as I have the +2A or +2B model.
The most strange portion of this mystery is everything was working fine a few weeks ago with the same components:
Maybe the SCART-to-HDMI unit failed?
All guesses accepted and appreciated.
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.
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.
Re: Blue tint video issue
Weird how it worked fine a few weeks ago when I first hooked it up. Looks like the parallel R44 resistor mod is in order then?
https://www.retrocomputershack.com/Tec ... ex.html
Thanks Mark
Last edited by 1024MAK on Sat Feb 27, 2021 11:11 am, edited 1 time in total.
Reason: Edited to tidy up quote tags
Reason: Edited to tidy up quote tags
Re: Blue tint video issue
Turns out I simply had a bad (new) HD converter unit which is brilliant news! The R44 mod didn't make a difference so I ordered a second HD converter.
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- Posts: 18
- Joined: Tue Oct 12, 2021 5:58 pm
Re: Blue tint video issue
You'll probably find the HDMI converter failed due to overheating - it's an idea to dismantle them and put heatsinks on the 2 main chips inside, and if possible drill some holes in the outer case to allow for airflow...
JD
JD