Aquarexperts... does the +12 and -12 only go to RAM?

[towmater]

I'm trying to crack this open to see if there is a fuse or obvious fault, but if you know that the 12 and -12 are only for ram, I'll just replace the systems memory with +5V only chips.

Edited January 30, 2021 by towmater

[towmater]

Checking schema, it's not the RAM, sorry. But if -12 is only for serial, I could live without that and use an internal 5v regulator, so that I might only feed her +12v?

[towmater]

After an hour of xacto scribing and heat-gun softening, I'm finally in. All I found was a cold solder joint, which after some remelting, gives us -22V, which I assume is close enough?

 

Should I change these caps?

Edited January 30, 2021 by towmater

[jltursan]

They don't look bulged or leaking at all; but if you've replacements, do it, they're 35 years old ?

 

With -22V you mean the -19V line isn't it?, if so, yes, seems appropiate as you must probably measured it without load, it'll drop a bit when connected.

Edited January 30, 2021 by jltursan

[MackJsy]

The +12 is used solely in the Video circuitry, specifically for the TEA 1002 and Modulator, the -12V for the Serial.

The entire board will run on +5V as long as you don't need the TEA (Using for example my RGB out) - however, the TEA is needed for the NTSC version, as the system clock is derived from there, the PAL version doesn't, as it comes from a seperate 7404 oscillator.

FYI, the 6116 SRAM chips are already 5v only, there is no DRAM (4116's) that uses silly voltages in this system

[towmater]

Is the schematic wrong here? I doesn't seem to be what's in my Aquarius, and I can't find a pinout of a 1041 Transistor.

[jltursan]

Maybe it's a D1041 NPN transistor?

[towmater]

5 hours ago, jltursan said:

Maybe it's a D1041 NPN transistor?

Perhaps, though a web search has zero results and subs in "D1047" as a result suggestion. The pinout of a 1047 seems to be correct.

[jltursan]

Check this: D1041 NPN Transistor

 

Beware it's TO-3, a "bulky" package transistor. If it's really this transistor, you must identify it easily.

 

[towmater]

On 2/11/2021 at 12:23 AM, jltursan said:

Check this: D1041 NPN Transistor

 

Beware it's TO-3, a "bulky" package transistor. If it's really this transistor, you must identify it easily.

 

It's a trap! Or a link back to this thread.

There's a 1061 transistor that's on the far opposite side of the board from AC in. The surrounding resistor components match the numbers around the "1041" to be the culprit. I think the schematic's just wrong.

 

I removed the -19V supply line, and the +6.6V incoming, and bypassed the +16v input, leaving only a +12V wall wart input.

 

Edited February 14, 2021 by towmater

[towmater]

On 1/31/2021 at 8:24 AM, MackJsy said:

(Using for example my RGB out) - however, the TEA is needed for the NTSC version, as the system clock is derived from there, the PAL version doesn't, as it comes from a seperate 7404 oscillator.

FYI, the 6116 SRAM chips are already 5v only, there is no DRAM (4116's) that uses silly voltages in this system

Not certain how to program an atf22v10, so I ordered a Sean Harrington board, which is "just" a composite amp, although it will hopefully get me to the point of verifying that the system works... the only RF tuner capable TV that I have is a 40" CRT that weighs 200lbs and hasn't left my garage floor for twenty years.

[jltursan]

21 hours ago, towmater said:

It's a trap! Or a link back to this thread.

There's a 1061 transistor that's on the far opposite side of the board from AC in. The surrounding resistor components match the numbers around the "1041" to be the culprit. I think the schematic's just wrong.

 

I removed the -19V supply line, and the +6.6V incoming, and bypassed the +16v input, leaving only a +12V wall wart input.

 

 

 

Ooops, missed the right link, sorry!. Here it is: D1041 NPN transistor

 

So, now, is it working only feeding it with +12V?

[towmater]

On 2/15/2021 at 12:31 AM, jltursan said:

So, now, is it working only feeding it with +12V?

Uhmmmm... I couldn't find a TV with a tuner that wasn't fubar. I tried an old GameGear TV tuner, but it couldn't even sync with known good RF signals, and flatscreens seem to fly right by the Aquarius modulator signal when "auto tuning". I ordered some parts from Mouser to build a composite amp so I will know better how it faired when that arrives. I have an Oscope standing by to troubleshoot if necessary. My main concern is running the 7805 so very hot, so I ordered a buck-convertor from Amazon.