14 Sep
2022
14 Sep
'22
4:25 a.m.
All,
I have a TVI-921C at the museum. I power it on and it beeps
continuously. One long, solid tone that does not stop until I power it
off. How do I start diagnosing this?
--
-Jon
+44 7792 149029
14 Sep
14 Sep
4:32 a.m.
Disconnect the speaker.
On Wed, Sep 14, 2022, 7:25 AM Jonathan Katz via cctalk <
cctalk(a)classiccmp.org> wrote:
All,
I have a TVI-921C at the museum. I power it on and it beeps
continuously. One long, solid tone that does not stop until I power it
off. How do I start diagnosing this?
--
-Jon
+44 7792 149029
4:44 a.m.
On Wed, 14 Sep 2022, Jonathan Katz via cctalk wrote:
I have a TVI-921C at the museum. I power it on and it
beeps
continuously. One long, solid tone that does not stop until I power it
off. How do I start diagnosing this?
Check the power supply voltages.
Mike Loewen mloewen(a)cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
9:12 a.m.
Mike Loewen wrote:
On Wed, 14 Sep 2022, Jonathan Katz via cctalk wrote:
After checking the voltages, if it has a microprocessor, check if it is being
held reset and if the clock is running.
If it is a big lump of logic, it would probably be a lot easier to deal
with if you can find some sort of service manual / circuit diagram /
circuit description.
Regards,
Peter Coghlan.
I have a TVI-921C at the museum. I power it on
and it beeps
continuously. One long, solid tone that does not stop until I power it
off. How do I start diagnosing this?
Check the power supply voltages.
9:55 a.m.
My snarky reply aside, in all seriousness...I discovered that I have one of
those terminals.
As others have said it could be the display circuit transformer's power but
not if it's a "beep" vs. a "squeal".
If you are getting a continuous beep it could be that you have a stuck key,
I'd verify that by carefully detaching the keyboard from the main board
(with the power off) and then powering on. If the beep is gone check your
keyboard.
Assuming it's not a stuck key, I'd guess you have a motherboard logic
error. I'd carefully remove the ROMS one at a time and then start testing
chips.
Here is mine
https://www.vintagecomputer.net/televideo/TVI-912C/Televideo_TVI-912C_pre-r…
Bill
On Wed, Sep 14, 2022 at 12:33 PM Peter Coghlan via cctalk <
cctalk(a)classiccmp.org> wrote:
Mike Loewen wrote:
On Wed, 14 Sep 2022, Jonathan Katz via cctalk
wrote:
After checking the voltages, if it has a microprocessor, check if it is
being
held reset and if the clock is running.
If it is a big lump of logic, it would probably be a lot easier to deal
with if you can find some sort of service manual / circuit diagram /
circuit description.
Regards,
Peter Coghlan.
I have a TVI-921C at the museum. I power it on
and it beeps
continuously. One long, solid tone that does not stop until I power it
off. How do I start diagnosing this?
Check the power supply voltages.
10:06 a.m.
Lots of Televideo docs scanned thanks to good old Al ==>
https://bitsavers.computerhistory.org/pdf/televideo/
Nothing for the 921 but there is an operator's manual for the 922 which may
shed some light on what the continuous beep might mean.
Sellam
On Wed, Sep 14, 2022 at 9:33 AM Peter Coghlan via cctalk <
cctalk(a)classiccmp.org> wrote:
Mike Loewen wrote:
On Wed, 14 Sep 2022, Jonathan Katz via cctalk
wrote:
After checking the voltages, if it has a microprocessor, check if it is
being
held reset and if the clock is running.
If it is a big lump of logic, it would probably be a lot easier to deal
with if you can find some sort of service manual / circuit diagram /
circuit description.
Regards,
Peter Coghlan.
I have a TVI-921C at the museum. I power it on
and it beeps
continuously. One long, solid tone that does not stop until I power it
off. How do I start diagnosing this?
Check the power supply voltages.
10:12 a.m.
Ahhh... Televideo. One of the best terminals I ever used was
the Televideo 910. Especially on Unix where it seemed Televideo
went out of their way to make TERMCAP based applications work
really well.
bill
11:03 a.m.
On 2022-09-14 1:06 p.m., Sellam Abraham via cctalk wrote:
Lots of Televideo docs scanned thanks to good old Al
==>
https://bitsavers.computerhistory.org/pdf/televideo/
Nothing for the 921 but there is an operator's manual for the 922 which may
shed some light on what the continuous beep might mean.
I have the "Televideo 912/920" service binder but I know it has stuff
for other models inside. There is a similar binder on bitsavers I
thought, but each one is probably slightly different. I can check inside
it to see if there's anything relevant.
(I own a TVI-920B.
https://www.flickr.com/photos/qu1j0t3/37328445552/in/photolist-2ms1g25-ZKXC…
)
--Toby
Sellam
On Wed, Sep 14, 2022 at 9:33 AM Peter Coghlan via cctalk <
cctalk(a)classiccmp.org> wrote:
> Mike Loewen wrote:
>> On Wed, 14 Sep 2022, Jonathan Katz via cctalk wrote:
>>
>>> I have a TVI-921C at the museum. I power it on and it beeps
>>> continuously. One long, solid tone that does not stop until I power it
>>> off. How do I start diagnosing this?
>>
>> Check the power supply voltages.
>>
>
> After checking the voltages, if it has a microprocessor, check if it is
> being
> held reset and if the clock is running.
>
> If it is a big lump of logic, it would probably be a lot easier to deal
> with if you can find some sort of service manual / circuit diagram /
> circuit description.
>
> Regards,
> Peter Coghlan.
>
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7 comments
7 participants
participants (7)
-
Bill Degnan -
Bill Gunshannon -
Jonathan Katz -
Mike Loewen -
Peter Coghlan -
Sellam Abraham -
Toby Thain