Would plugging in a 9v @ 1.5amps damage my ZX80. This is the power supply I use for my ZX81, but my ZX81 has a lot of extra hardware attached so I bought this PSU with extra amps to handle the load.
Anyway, my ZX80 seems dead now. Plugging in a more conservative 9v @ 0.65 amp doesn't fix the issue.
Phil
ZX80 troubles
Re: ZX80 troubles
Well the ZX80, just as the ZX81 has a 7805 as a voltage regulator.
The higher the input voltage is, the hotter it gets. But it doesn't brake immediately.
It does handle quite high voltages (24V for example) if the token current is not too high (which it isn't in a ZX80).
If the PSU is capable of giving 1.5amps, then, if not regulated, it will give more than the usual 12V of the Sinclair PSU.
But that should not damage your ZX80 as stated above.
What a 7805 does not like is a negative voltage. Hopefully your PSU is clear of that.
Does your ZX81 work with this PSU? Then the polarity will be ok.
Maybe the malfuction was not caused by the PSU.
As all of the ICs of the ZX80 are still available there is good hope that i will be running again.
Can you check the polarity of the PSU?
Can you measure the voltages at the tree pins of the 7805?
That would help with the diagnosis.
Paul
The higher the input voltage is, the hotter it gets. But it doesn't brake immediately.
It does handle quite high voltages (24V for example) if the token current is not too high (which it isn't in a ZX80).
If the PSU is capable of giving 1.5amps, then, if not regulated, it will give more than the usual 12V of the Sinclair PSU.
But that should not damage your ZX80 as stated above.
What a 7805 does not like is a negative voltage. Hopefully your PSU is clear of that.
Does your ZX81 work with this PSU? Then the polarity will be ok.
Maybe the malfuction was not caused by the PSU.
As all of the ICs of the ZX80 are still available there is good hope that i will be running again.
Can you check the polarity of the PSU?
Can you measure the voltages at the tree pins of the 7805?
That would help with the diagnosis.
Paul
In theory, there is no difference between theory and practice. But, in practice, there is.
Re: ZX80 troubles
Thanks Paul,
Anyway, problem solved. I took the readings from the 7805 and all seemed ok. I removed the ROM and reinserted it...that fixed it right up.
Although I am having much trouble loading a wav file from either my PC or my Mac. Can't get it to work at all...I had done this before with no problem. Strange.
Sometimes the machine will do nothing, and other times it will drop back to the cursor prompt and also display some weird artifacts.
I'll try to get some pictures to show.
Phil
Anyway, problem solved. I took the readings from the 7805 and all seemed ok. I removed the ROM and reinserted it...that fixed it right up.
Although I am having much trouble loading a wav file from either my PC or my Mac. Can't get it to work at all...I had done this before with no problem. Strange.
Sometimes the machine will do nothing, and other times it will drop back to the cursor prompt and also display some weird artifacts.
I'll try to get some pictures to show.
Phil