Zero88 BetaPack MKI Repair

[Nutnode]

Hi all,

 

I recently volunteered myself & a friend to undertake the repair of some disused MK One Betapacks. The packs had been set aside long ago, with as far as anyone can remember - 'no channels working'. The threads on this forum proved invaluable as a source of information resulting in all three packs being restored to a fully operational state. I thought it might be beneficial to feedback here info on the components we used & from where as an up to date guide for anybody attempting the same. I am an electrician & my friend trained as a video & television service bench engineer, so between us we have a good level of knowledge & experience, but any of these repairs could be attempted by a competent hobbyist. Most of these components are as previously listed in various posts around these forums & wiki. I ordered…

Vishay CCF60 Series E36 Axial Metal Film Fixed Resistor 100kΩ ±1% 1W ±100ppm/K

RS Stock no.:830-9201

Panasonic Aluminium Electrolytic Capacitor 10μF 35V dc Through Hole M Series Aluminium, Through Hole Electrolytic

RS Stock no.:228-6717

RS Pro 10A Ceramic Cartridge Fuse, F, 6.3 x 32mm

RS Stock no.:413-248

MULTICOMP PPFH-6132 Fuseholder, 6.3mm x 32mm, 20A PPFH-6132

CPC Stock no.:FF02304

(Please note this panel fuse holder is NOT a direct replacement and required slight filing of the panel. I purchased due to no stock availability of exact part)

Single Channel Triac Opto Coupler

RS Stock no.:161-1015

240v/23v Main PCB Transformer (Salvage unit)

Ian Knight - TheServiceGuy

I also ordered, but we did not need to fit…

ON Semi 2N3904TA NPN Transistor, 200 mA, 40 V, 3-Pin TO-92

RS Stock no.:739-0442

 

BTA25-600B STMicroelectronics, TRIAC, 800V 25A, Gate Trigger 1.3V 100mA, 3-Pin RD-91

RS Stock no.:829-4014

We approached the repairs by changing out all of the commonly prone to failure parts regardless of the state of the existing ones. A swift initial check did reveal some of the sync circuit resistors with bad values, so we deemed it less time consuming to just swap out everything. We did not swap the transistors because working without a circuit diagram & incomplete labelling of components printed on the board we were not 100% certain on which transistors to swap, so we skipped them. We also held off on the triacs (as these are the most expensive unit price) until we knew we had eliminated the typical cause of failures on the main boards. As it happened, none needed replacement. All opto couplers were replaced - easy DIL sockets on the triac boards. Many of the old fuse holders had overheated & become brittle, we replaced these, and rewired from the incoming power with tri-rated 2.5mm cable. One board mounted transformer had failed, but we located a salvaged used one which worked fine.

All told, the repairs took about a day and a half, including a soak test - but we now have 18 additional channels for minimal cost,

I do now have a stock of some spares which I'd be happy to sell on at a reduced price. Feel free to get in touch…

Stephen.

 

[boatman]

The schematics for the Betapack can be found here:

 

https://elektrotanya.com/zero88_lighting_ltd._betapack_mk1_em5938_em5949_em5830_em6298_iss7_iss4_iss3_sch.pdf/download.html

[Nutnode]

The schematics for the Betapack can be found here:

 

https://elektrotanya...f/download.html

 

Thanks Boatman, will keep that for future reference & may even open one up again just to educate my self on using my scope that I picked up second hand seeing as the expected waves are shown… I'm aware I need to get out more! ** laughs out loud ** ;)

 

Hopefully we're all set now to use the units in production - summer rep will be the real test, but I'm happy with where we're up to & always believe its worth giving back & sharing experience for others.

 

Stephen.

[DrV]

The schematics for the Betapack can be found here:

 

https://elektrotanya...f/download.html

 

Thanks Boatman, will keep that for future reference & may even open one up again just to educate my self on using my scope that I picked up second hand seeing as the expected waves are shown… I'm aware I need to get out more! ** laughs out loud ** ;)

 

Hopefully we're all set now to use the units in production - summer rep will be the real test, but I'm happy with where we're up to & always believe its worth giving back & sharing experience for others.

 

Stephen.

At the risk of teaching grandma to suck eggs, it bears repeating (in the interests of safety) that you can't do much oscilloscope examination of the mains side waveforms without running the dimmer from an isolating transformer.

 

Dave

[Nutnode]

Thanks Dave, worthwhile advice. :)

[kgallen]

Vishay CCF60 Series E36 Axial Metal Film Fixed Resistor 100kΩ ±1% 1W ±100ppm/K

RS Stock no.:830-9201

 

Hi,

 

I'm not sure you've fitted the correct spec of resistor here I'm afraid. If these are the potential divider resistors in the phase sync circuit - and from the 1W info above it suggests they are - then they are across the mains and need to be VR68 spec parts rather than "normal spec" resistors. This is the correct RS item, and as you can see from their listing, a more expensive part (60p each rather than 10p each):

 

https://uk.rs-online...oducts/6835297/ (Vishay VR68 Series Axial Fixed Resistor 100kΩ ±5% 1W ±200ppm/°C) RS: 683-5297

 

You might need to take a look at these again, sorry. Worth also checking with Keith Rogers, the Service Manager at Zero88, for other parts. Also Ian Knight (Service Guy) you've had other parts from will be able to advise.

 

Also if I can be cheeky enough to quote from a post (or sequence of posts) I've made on the Zero88 forum over the years, here is some spares info (sorry that it might duplicate some of your original list and prices out of date):

 

1/4" x 1 1/4" (6.35mmx32mm) 10A quick blow HRC fuse e.g. SIBA 70-065-63 10A

Farnell: 117-5122 RS: 413-248 CPC: FF02367 49p ea but MOQ=10.

 

Betapack 1 fuseholder: RS 197-9519, Farnell 121-4783 (cap), 121-4782 (spade rather than solder terminals)

 

Betapack 1 UK 15A replacement front panel sockets: Stage Electrics order code 658-4621 (£3.91+VAT ea. at Jan 2010)

According to Keith @Zero88, this socket is also used on early BP2's. Later BP2 and BP3 use a Zero88 custom-made socket.

 

Triac BTA40-600B is Farnell code 980-1715 (£6.39+VAT ea. at Jan 2010) - Fuse-protected Betapacks can use BTA25-600B which you might find slightly cheaper at some suppliers (e.g. CPC SC07588 £4.84+VAT). BTA40 must be used for MCB-protected Betapacks

 

Triac board opto-coupler MOC3052-M (6-pin DIP-W) is Farnell code 146-7848 (£1.18+VAT ea. at Jan 2010). (This part is a suitable replacement for the obsolete MOC3021 used on early BP1's).

 

Looking for some triacs for Betapack, I notice RS don't do BTA25-600B, but they do do BTA40-600B: http://uk.rs-online....triacs/1270654/ @ £5.86+VAT

Note: Don't be tempted by BTA26-600B as it's the wrong package! [Nearly fell for that one until I checked the datasheet!]

CPC still do the BTA25-600B: http://cpc.farnell.c...d-91/dp/SC07588 @£6.23+VAT

 

100k sync timing resistors for BP1/BP2 must be VR68 rated 1W, e.g:

http://uk.rs-online....oducts/6835297/ @ £0.60+VAT each (min order qty 10)

 

Hope that helps.

 

Kevin

 

Original Zero88 Forum posts: http://zero88.com/fo...t&comment=23073

[Nutnode]

Hi Kevin,

 

Oh! Ok, that'll be my error, will investigate further. Thank you for pointing that out. They are the sync circuit ones, what we have fitted is functioning, but want to get it right so will check that out. I must confess Im not familiar with that part of the rating, maybe why I glossed over it slightly when searching out the parts… D'oh!!

 

No problem adding the info here again in this thread, as Ive mentioned in o/p we gained a lot of info to get us this far from these pages & I believe in sharing this sort of knowledge. It's seems to be a perennial topic of discussion and worthy of a 'bump' now and then ;)

 

Regards, Stephen.

[vinntec]

At my theatre I used 11 channels of 2 x Betapack Mk1 in a show which closed Saturday! There is still plenty of life left in them, even if all the others are Mk3 now.

[kgallen]

Oh! Ok, that'll be my error, will investigate further. Thank you for pointing that out. They are the sync circuit ones, what we have fitted is functioning, but want to get it right so will check that out. I must confess Im not familiar with that part of the rating, maybe why I glossed over it slightly when searching out the parts… D'oh!!

 

I neglected to declare it's because I made exactly the same mistake! Anyone need any "normal" 100k 1W resistors?! http://www.blue-room.org.uk/public/style_emoticons/default/biggrin.gif

[Nutnode]

Oh! Ok, that'll be my error, will investigate further. Thank you for pointing that out. They are the sync circuit ones, what we have fitted is functioning, but want to get it right so will check that out. I must confess Im not familiar with that part of the rating, maybe why I glossed over it slightly when searching out the parts… D'oh!!

 

I neglected to declare it's because I made exactly the same mistake! Anyone need any "normal" 100k 1W resistors?! http://www.blue-room.org.uk/public/style_emoticons/default/biggrin.gif

 

You can go off people…! :) ;) ** laughs out loud **

(I presume you're referring to the 12 I now have surplus…!)

[kgallen]

(I presume you're referring to the 12 I now have surplus…!)

Nope, referring to the 10+ I have surplus having also initially purchased standard 1W metal film resistors before finding out from Keith@Zero88 or Ian@ServiceGuy that they should be VR68 parts required for their voltage spec because it's a 'safety' related component! Fortunately I think I'd only done one pack of the four I was doing. Actually I think early Betapack 1s might not have used the VR68 spec at new build, but I understand that was changed fairly early on.

At which point I should note that you should replace all four resistors at the same time not just the ones that appear broken. If Ian joins this thread he'll confirm that.

Kevin

 

 

[ianknight]

(I presume you're referring to the 12 I now have surplus…!)

Nope, referring to the 10+ I have surplus having also initially purchased standard 1W metal film resistors before finding out from Keith@Zero88 or Ian@ServiceGuy that they should be VR68 parts required for their voltage spec because it's a 'safety' related component! Fortunately I think I'd only done one pack of the four I was doing. Actually I think early Betapack 1s might not have used the VR68 spec at new build, but I understand that was changed fairly early on.

At which point I should note that you should replace all four resistors at the same time not just the ones that appear broken. If Ian joins this thread he'll confirm that.

Kevin

 

Yes - Kevin's correct, it's false economy to only swap out one pair of the resistors as you'll end up swapping the other pair 4 weeks later (got a faded tee shirt for that one) so whilst you have the board out - do them both.

 

The BTA40-600B is the 'go to' triac - it's 40amp rated rather than the 25amp of the original and I've been fitting them for years (though I will admit to having some of the 25amp version in my spares stock from salvaged units).

 

If anyone's reading this thread and thinking "I've got old Betapacks but I don't feel confident doing what that guy did - my solderings rubbish..." then I can help... I don't cost the earth :)

[swenk]

hi.

 

just repairing a pile of these (the plus version). Any reason the 32mm fuse is a 32mm fuse and not a 20mm fuse?

 

I was thinking about replacing them as I can almost always source 20mm fuses, but whenever I go to the cupboard for a 32mm they have almost always run out and the merchants round here never carry any.

 

if there is a designed safety factor then obviously I'll replace them with new 32mm holders as a lot of the little carriers are missing in this set.

[sandall]

Best to speak to Zero88 (cue Mr Hole :)), but I think I got my replacement fuses & carriers from RS

[Edward- Z88]

Hello,

 

The channel fuses were 32mm to aid with heat dissipation if a high current is drawn from the channel for a long duration of time.

If you wish to replace with the easy to source 20mm do so at your own risk. http://www.blue-room.org.uk/public/style_emoticons/default/rolleyes.gif

 

Any queries let me know.

 

Edward