How long does it take for a Master to start up

discuss both original and modern hardware for the bbc micro/electron
Post Reply
linus222
Posts: 9
Joined: Fri Feb 07, 2020 1:04 pm
Contact:

How long does it take for a Master to start up

Post by linus222 » Tue Feb 11, 2020 11:00 am

Hi,

I was wondering, when I switch on my Master first time after a day or two it takes about 10 to 15 seconds to the "beeb". But when I switch off wait a few seconds and switch on again it takes a seconds till the "beeb".

Is that normal behavior or should I be worried about the PSU?
It has been recapped, at least C1 and C2. But i am not quite sure about C9.

Can someone with a normal working Master acknowledge the starting behavior?

cheers
Alexander

User avatar
danielj
Posts: 8155
Joined: Thu Oct 02, 2008 5:51 pm
Location: Manchester
Contact:

Re: How long does it take for a Master to start up

Post by danielj » Tue Feb 11, 2020 11:21 am

Should be pretty much instant. I'd look at changing C9...

linus222
Posts: 9
Joined: Fri Feb 07, 2020 1:04 pm
Contact:

Re: How long does it take for a Master to start up

Post by linus222 » Tue Feb 11, 2020 11:36 am

Thanks, then I better change it.

User avatar
1024MAK
Posts: 9988
Joined: Mon Apr 18, 2011 5:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: How long does it take for a Master to start up

Post by 1024MAK » Tue Feb 11, 2020 7:59 pm

If I switch on one of my Masters and a modern LCD TV both at the same time, the Master has started up and waiting for input from me long before the TV is ready...

Seriously normally a Master starting up (when not configured to load a file from disk) takes less than one second.

Mark

linus222
Posts: 9
Joined: Fri Feb 07, 2020 1:04 pm
Contact:

Re: How long does it take for a Master to start up

Post by linus222 » Thu Feb 27, 2020 3:32 pm

Hi,

I now changed the capacitor C9. The Master now starts faster but not fast. Now it takes 5-10 seconds to start up.
i think I better have a look at the 180k Resistors

Quite hard to get 180k 2W resistors. It stops at 2.2k at my local reseller.

User avatar
CMcDougall
Posts: 7049
Joined: Wed Feb 02, 2005 3:13 pm
Location: Shadow in a Valley of Scotland
Contact:

Re: How long does it take for a Master to start up

Post by CMcDougall » Thu Feb 27, 2020 7:25 pm

try checking the output of the +5v when it's on

there is pots you can turn to get to 5v on side of PSU

could be that :?
ImageImageImage

User avatar
danielj
Posts: 8155
Joined: Thu Oct 02, 2008 5:51 pm
Location: Manchester
Contact:

Re: How long does it take for a Master to start up

Post by danielj » Thu Feb 27, 2020 8:01 pm

If you suspect the PSU, and can't be bothered to fully diagnose it, you could just replace it with a modern Meanwell unit - I've done this in mine and it's excellent:

https://www.waitingforfriday.com/?p=794

Check the voltages though!

d.

linus222
Posts: 9
Joined: Fri Feb 07, 2020 1:04 pm
Contact:

Re: How long does it take for a Master to start up

Post by linus222 » Mon Mar 16, 2020 11:10 am

I finally sorted out my problems with the PSU.

Found some old 180k 2W resistors in my stash (I bought 4kg of electronic-parts from a vendor for cheap some years ago)
And I bought 2 new 100uF 250V capacitors and replaced them in the PSU. When I removed them I could see they were leaking all over the place and I had to carefully clean up the mess. The green coating comes loose quite easily on these old PCB's.

It was a bit of a scare to switch the computer on and get an instant beep since i was accustomed to wait quite a few seconds for it to start up.

Now I am playing around with EEPROMs in my new cartridges (thanks again Dave H) and wait for the new GOTEK to arrive.

cheers
A.

User avatar
1024MAK
Posts: 9988
Joined: Mon Apr 18, 2011 5:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: How long does it take for a Master to start up

Post by 1024MAK » Mon Mar 16, 2020 1:35 pm

👍 8)

Mark

User avatar
egel
Posts: 84
Joined: Mon Nov 25, 2019 1:10 pm
Location: Almere, Flevoland, The Netherlands
Contact:

Re: How long does it take for a Master to start up

Post by egel » Tue Mar 17, 2020 4:49 pm

danielj wrote:
Thu Feb 27, 2020 8:01 pm
Check the voltages though!
In what range should the voltages be?
Mine are 4,9 V, -4.9 V and 12,5 V.

User avatar
1024MAK
Posts: 9988
Joined: Mon Apr 18, 2011 5:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: How long does it take for a Master to start up

Post by 1024MAK » Tue Mar 17, 2020 5:05 pm

They are fine.
The +5V should be between 4.85V and 5.15V
The -5V and +12V should be +/-10%.

Mark

Post Reply

Return to “8-bit acorn hardware”