Search found 42 matches

by RS232
Mon Jun 10, 2019 12:24 am
Forum: Hardware
Topic: HELP i was trying to replace caps now i have issues!
Replies: 2
Views: 967

HELP i was trying to replace caps now i have issues!

I gave bbc een trying to replace the caps on my 48k spec issue 3b. Problem when powering up i get red lines then restart then copywrite notice and repeat. Finally eirther stops black screen or a few colour squares.

Any advice appreciated

Thanks!
by RS232
Mon Apr 22, 2019 10:14 pm
Forum: Hardware
Topic: Composite mod done Zx81 great picture but somethkng is wrong
Replies: 14
Views: 1688

Re: Composite mod done Zx81 great picture but somethkng is wrong

[Re your message thanks all working, it looks like a minor fault with my tv Many thanks all quote=1024MAK post_id=33905 time=1555954985 user_id=1212] The transistor you used. In one of your other threads, I can see that it is marked BC108B. See no -B in photo just before this post, but yes I noticed...
by RS232
Mon Apr 22, 2019 2:53 pm
Forum: Hardware
Topic: Composite mod done Zx81 great picture but somethkng is wrong
Replies: 14
Views: 1688

Re: Composite mod done Zx81 great picture but somethkng is wrong

Attached is the mod applied.. i'm dipping my toe in the water of doing electronics didn't realize it could get so troublesome.. i wonder if it is the BC108 i am using and not the BC108B i should have in place.. sigh
by RS232
Mon Apr 22, 2019 12:40 pm
Forum: Welcome Area
Topic: Hello all! Nice to be here!
Replies: 4
Views: 1119

Re: Hello all! Nice to be here!

Welcome there are some helpful people in this forum
by RS232
Mon Apr 22, 2019 11:58 am
Forum: Hardware
Topic: Composite mod done Zx81 great picture but somethkng is wrong
Replies: 14
Views: 1688

Re: Composite mod done Zx81 great picture but somethkng is wrong

Replaced cap, soldered negative side to video out. I used a 10v 100uf for this. Got rid of the extra wire Insulated both cap and resister together soldered to transistor. I have noticed the screen still does the screen issue not as often. Now every 5 to 15 minutes. So problem has still not completly...
by RS232
Mon Apr 22, 2019 12:06 am
Forum: Hardware
Topic: Composite mod done Zx81 great picture but somethkng is wrong
Replies: 14
Views: 1688

Re: Composite mod done Zx81 great picture but somethkng is wrong

Great that makes a lot of sence , gonna try it and ket you know thw outcome

Thanks
by RS232
Sun Apr 21, 2019 8:16 pm
Forum: Hardware
Topic: Composite mod done Zx81 great picture but somethkng is wrong
Replies: 14
Views: 1688

Re: Composite mod done Zx81 great picture but somethkng is wrong

I went for a transister to cap and resister mod.. see pics re the mod and the ULA. Overheating ULA really requires a heat sink? I have replaced the regulator already to cut down the heat. Hope you are able to make out the pics.. and advise. Note i see Sinclair decided not to fit two resistors next t...
by RS232
Sun Apr 21, 2019 1:31 pm
Forum: Hardware
Topic: Composite mod done Zx81 great picture but somethkng is wrong
Replies: 14
Views: 1688

Composite mod done Zx81 great picture but somethkng is wrong

Hi all i have spent two days modifying my zx81 and gone through some highs and lows. :o I have done a recommended composite mod on my issue 3 Zx81 and the picture quality looks great. One problem now exists after the device is on for 5 mins the video turns off and on no data loss but disruptive. It ...
by RS232
Thu Apr 18, 2019 12:47 pm
Forum: Hardware
Topic: Zx81 from death to life??
Replies: 17
Views: 1717

Re: Zx81 from death to life??

Omg i have much to learn. Thanks will try the points raised. :shock: :o :idea: :D