ukVac.com Homepage
Forum Home Forum Home > Technical > Tech, Maintenance & Repairs
  New Posts New Posts RSS Feed - Hantarex polo2 repair help (SORTED)
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Skin:


Hantarex polo2 repair help (SORTED)

 Post Reply Post Reply Page  123 4>
Author
Message
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Topic: Hantarex polo2 repair help (SORTED)
    Posted: 25 Feb 2018 at 4:41pm
Looking for some help pleaseSmile

28" Hanty polo2 psu is tripping can hear the feint tick, have read this can be the hot gone short? No signs of the flyback melting! As this is a polo2 not sure where the hot is? Any help getting started with this greatly appreciated.

Cheers Ronnie


Edited by Ronnie Dent - 15 Mar 2018 at 1:36pm
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 9:25am
Would like to check the B+ with a 60w bulb, from what I understand if I remove the yoke plug that will isolate the B+ from the hot? But then I need to connect the lamp to ground and one of the 2 pins on the yoke sockets? Is that correct? which pin? I know it's one of the two that are bridged.

Thanks Ronnie
Back to Top
obcd View Drop Down
Senior Member
Senior Member


Joined: 02 Aug 2014
Location: Belgium
Status: Offline
Points: 1525

Feedback: 0
Post Options Post Options   Thanks (0) Thanks(0)   Quote obcd Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 12:10pm

I usually connect to one of the large capacitors just outside the power supply cage. If I remember well, the Yoke plug disconnects the drive voltage from the hot stage, but I can't remember if that's really the B+ voltage. If your chassis is a dual frequency, it should have some power fet's on the vertical pcb in the supply cage. If the hot becomes short, one of those fet's usually shorts as well.

Make sure you check the 2 smaller capacitors in the power supply section. One tends to have the issue that the B+ voltage raises with 20 - 30V when it becomes bad. The HOT can handle this for a while but will soon or later give up.
 
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 12:18pm
Thanks obcd, I'm going to need to remove the monitor from the machine and ideally remove the chassis to work with on the bench. I thought it might be best to load the B+ with a lamp to verify it's good or bad, but will need to know how to do this properly before I start. And yes this is the 15/25 switching chassis.

Thanks Ronnie
Back to Top
obcd View Drop Down
Senior Member
Senior Member


Joined: 02 Aug 2014
Location: Belgium
Status: Offline
Points: 1525

Feedback: 0
Post Options Post Options   Thanks (0) Thanks(0)   Quote obcd Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 12:44pm
We have a time crisis 2 with 2 of those polo 2's.
I probably already spent more time at the back of that machine instead of the front.
Finally added 2 additional fans to keep the chassis area cool. Untill now, fingers crossed...


Edited by obcd - 26 Feb 2018 at 12:45pm
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 1:13pm
Oh dear! problematic then, I will try and check the hot for shorts once I get the chassis out, I guess removing the hot will be good enough to run the B+ with a lamp to see if it's stable and correct? again I'm not sure what voltage to expect from the polo2? 138v with no signal?

Thanks Ronnie
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 1:46pm
Just removed the chassis and checked T22 which I think is the hot it's reading 1 ohm from leg 1 over to leg 3 but not short from leg 2 to either 1 or 3? guess I need to remove it
Back to Top
obcd View Drop Down
Senior Member
Senior Member


Joined: 02 Aug 2014
Location: Belgium
Status: Offline
Points: 1525

Feedback: 0
Post Options Post Options   Thanks (1) Thanks(1)   Quote obcd Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 3:35pm
If I remember well, it's a BCE transistor. Base emiter should measure 0.7 in one direction and infinitive in the other direction. Collector emitter should measure infinitive.
Finding the correct B+ voltage on the schematics is difficult as they are the same for different size of tubes, using different B+ voltages. Replacing the 2 smaller electrolitic capacitors in the power supply section might not hurt, even if they are still ok. You might see on their solderings if they are still original. They don't cost an arm and a leg. (I know you are scottish, sorry, couldn't resist)
 
Make sure you also check the IRF5(6)30 power mosfets on the vertical board of the power supply cage. Usually, if the hot is shorted, one of those has a short as well.
 
Finally, if you might need another lopt, be carefull where you buy it. I already received twice a bad chinese lopt. One had a broken screen adjustment and the other showed a vertical jailbar in the picture a couple of inches from the left of the screen. I assume gunblade might still have some lopt transformers for those.
Back to Top
gunblade View Drop Down
Senior Member
Senior Member


Joined: 25 Jul 2011
Status: Offline
Points: 1599

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote gunblade Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 3:43pm
all the polo 2 flybacks have this jailbar issue with bright white screens, not so bad on the chassis with 12 ohm resistor on neck card
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 6:54pm
(I know you are scottish, sorry, couldn't resist)

Lol this is very true but I think I will have those capacitors already and will change them for sure!

Well it would seem the hot is bad but I will remove it and check it out of the board. Will also look at those fets and see if I can compile a shopping list.

Grant would the polo 1 cap list you gave me apply to this polo 2 chassis?

Back to the B+ with the hot removed I will try the lamp connected to one of the capacitors + side at the front of the cage, and if this works and is stable would this prove the fets to be good?

Thanks for your input guys

Cheers Ronnie
Back to Top
gunblade View Drop Down
Senior Member
Senior Member


Joined: 25 Jul 2011
Status: Offline
Points: 1599

Feedback: 5
Post Options Post Options   Thanks (1) Thanks(1)   Quote gunblade Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 6:57pm
different caps on polo 2
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 7:00pm
Originally posted by gunblade gunblade wrote:

different caps on polo 2


Ok thanks Grant
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 7:49pm
This chassis only has 2 fets fitted not 4? The lower one seems to be short!


Back to Top
gunblade View Drop Down
Senior Member
Senior Member


Joined: 25 Jul 2011
Status: Offline
Points: 1599

Feedback: 5
Post Options Post Options   Thanks (1) Thanks(1)   Quote gunblade Quote  Post ReplyReply Direct Link To This Post Posted: 26 Feb 2018 at 8:31pm
yep that's normal if the HOT is short, change both
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2018 at 10:17am
Just removed the HOT (T22) It's reading short from pins 1 to 3? all other combinations I get about 250 ohms, so I'm thinking this is bad? It has no markings but is the complete plastic package.

So after this I connected my lamp to the + of C19 and ground and the psu runs and lights the lamp, voltage measures 115vdc, Does this tell me the fets are good? or should I source new one's anyway?

Thanks Ronnie
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2018 at 11:26am
T22 in the manual is BU2520A is this correct?

T1 FET IRF630
T6 FET I (diode symbol) R351N?? where to find this one?

Thanks Ronnie
Back to Top
gunblade View Drop Down
Senior Member
Senior Member


Joined: 25 Jul 2011
Status: Offline
Points: 1599

Feedback: 5
Post Options Post Options   Thanks (1) Thanks(1)   Quote gunblade Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2018 at 12:37pm
t22 and t6 will be short, t6 is the irf630 under t1 on the switching board
bu2520a or 2525a will do, you can use aw as well
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2018 at 12:43pm
Originally posted by gunblade gunblade wrote:

t22 and t6 will be short, t6 is the irf630 under t1 on the switching board
bu2520a or 2525a will do, you can use aw as well


Thanks Grant yes T6 is the IRF630 sorry.

Is there any chance you could supply these Grant? bit cheeky I know as your a repairer not a supplier but I will know the parts are reputable. Or a decent source link?

Cheers Ronnie
Back to Top
Ronnie Dent View Drop Down
Senior Members
Senior Members
Avatar

Joined: 23 Dec 2007
Location: Scotland
Status: Offline
Points: 7238

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ronnie Dent Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2018 at 1:14pm
Back to Top
obcd View Drop Down
Senior Member
Senior Member


Joined: 02 Aug 2014
Location: Belgium
Status: Offline
Points: 1525

Feedback: 0
Post Options Post Options   Thanks (0) Thanks(0)   Quote obcd Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2018 at 3:47pm
Some of the BU2520XX transistors have a lower maximum power dissipation. Make sure you order one with at least the same maximum power dissipation as the original that was mounted.
Back to Top
 Post Reply Post Reply Page  123 4>
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.943 seconds.