HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: rzleromer
New Today: 1
New Yesterday: 2
Overall: 12584

People Online:
Members: 1
Visitors: 81
BOT: 2
Total: 84
Who Is Where:
 Members:
01: Vince > Forums
 Visitors:
01: Home
02: Forums
03: Photo Albums
04: Forums
05: Forums
06: Home
07: Forums
08: Forums
09: Forums
10: Forums
11: Forums
12: Forums
13: Forums
14: Forums
15: Forums
16: Photo Albums
17: Home
18: Forums
19: Your Account
20: Forums
21: Forums
22: Photo Albums
23: Forums
24: Forums
25: Forums
26: Your Account
27: Forums
28: Forums
29: Forums
30: Forums
31: Forums
32: Forums
33: Forums
34: Forums
35: Forums
36: Forums
37: News
38: Forums
39: Forums
40: Forums
41: Forums
42: Forums
43: Forums
44: Forums
45: Forums
46: Forums
47: Forums
48: Forums
49: Photo Albums
50: Forums
51: Forums
52: Forums
53: Home
54: Forums
55: Forums
56: Photo Albums
57: Forums
58: Home
59: Forums
60: Forums
61: Forums
62: Your Account
63: Forums
64: Forums
65: Forums
66: Forums
67: Photo Albums
68: Forums
69: Photo Albums
70: Forums
71: Photo Albums
72: Forums
73: Forums
74: Forums
75: Forums
76: Forums
77: Forums
78: Your Account
79: Forums
80: Forums
81: Forums
  BOT:
01: Your Account
02: Forums

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 305
 Pictures: 2357
  · Views: 355632
  · Votes: 1306
  · Comments: 85
 

Support our Advertisers

RCBS ammoMaster Chrono repair.
Discussion regarding the reloading of ammunition and tuning of loads for accuracy
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition

View previous topic :: View next topic  
Author Message
gelandangan
Super Member
Super Member


Joined: May 07, 2006
Posts: 5834
Location: Sydney Australia

PostPosted: Sun Feb 23, 2014 8:38 pm    Post subject: RCBS ammoMaster Chrono repair. Reply with quote

Got a mate in real distress.
His RCBS chrono died out of a sudden, when he need to check his load for an IPSC comp.
The unit he brought the unit to me it is dead as door post.
A quick test on the power input show that there is a short circuit in the unit somewhere.
So, I opened the damned thing.



Opening the unit, my first impression is that it is definitely very cheaply made.
Absolutely do not worth the price tag.
It is a PCboard within cheap plastic enclosure shaped in fancy bullet style .
The buttons are membrane type which are good only for a short amount of push, and the membrane switch is GLUED on to the cheap plastic, thus made it not repair friendly.

First scanning for the obvious problem such as corrosion, dirt accumulated between pins or other usual problems.
Nope, beside some oxidized lacquer near the PCB, the whole board looks Ok.

Here are the pictures of the board front and back




And here are pictures of the Piece of S membrane switch.

[


_________________
A straight line is the shortest distance between two points.
A smile is the shortest distance between two people.

The government I trust .. is my .45-70 Government.

Do - Not try!


gelandangan.weebly.com/


Last edited by gelandangan on Sun Feb 23, 2014 8:54 pm; edited 1 time in total
Back to top
View user's profile Visit poster's website
gelandangan
Super Member
Super Member


Joined: May 07, 2006
Posts: 5834
Location: Sydney Australia

PostPosted: Sun Feb 23, 2014 8:53 pm    Post subject: Re: RCBS ammoMaster Chrono repair. Reply with quote

Using my lab power supply I try to power up the unit and it swallowed up a whooping 6 Amps 9 volt (almost 60 WATTS !!) onto the board Shocked
My hands bangs on to the table trying as fast as possible to remove the power. Ouch!

Next touching each of the power device with temperature probe to find where the 60 watts is sinking to, I found that the large MOSFET (AMP3095P) near the power input is heated up.
This mosfet is rated 30V/6A, I wonder why in the world you would need such a large MOSFET in a small battery operated device?
I digress..

So hooking up my scope, I isolate and test trigger the mosfet, and it works Ok. Hmmm..
Lets test the ESR of the accompanying capacitor.. and AHA!!
The goddam capacitor shorted down to 2 ohm.



So I replaced the capacitor and now the unit works again.

All in all it is a simple repair, but for the price you paid for the piece of crap chrono, you would expect the company uses better rated parts.

My suggestion if you want to buy one of these, you will be much better off buying a Chrony instead.

_________________
A straight line is the shortest distance between two points.
A smile is the shortest distance between two people.

The government I trust .. is my .45-70 Government.

Do - Not try!


gelandangan.weebly.com/
Back to top
View user's profile Visit poster's website
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 4463
Location: NC foothills

PostPosted: Mon Feb 24, 2014 12:05 am    Post subject: Re: RCBS ammoMaster Chrono repair. Reply with quote

Good info Gelan, thanks!

_________________
Mike

"I ain't no better than anyone else, and there ain't no one better than me!" Ma Kettle

Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Vince
Super Member
Super Member


Joined: May 25, 2005
Posts: 13489
Location: Brisbane AUSTRALIA

PostPosted: Mon Feb 24, 2014 6:53 am    Post subject: Re: RCBS ammoMaster Chrono repair. Reply with quote

That's good to know Gelan...thanks for that mate. I have looked at these units in the past and thought they looked a little too "gimmicky" for me...now it seems that they are cheap and nasty inside as well.

_________________
Cheers, Vince Cheers

Illegitimi non carborundum
(Never let the bastards grind you down)

Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God.

"Nulla Si Fa Senza Volonta."
(Without Commitment, Nothing Gets Done)
Back to top
View user's profile AIM Address MSN Messenger Yahoo Messenger Photo Gallery
dhc4ever
Super Member
Super Member


Joined: May 26, 2011
Posts: 2335
Location: Ipswich, Queensland Australia

PostPosted: Mon Feb 24, 2014 1:43 pm    Post subject: Re: RCBS ammoMaster Chrono repair. Reply with quote

My club has a dead one of these sitting in the corner, didnt last long at all.
My first question was why didnt we just buy another chrony, cost less and seem to last quite well until you shoot them.

_________________
Pete

Dont do anything you wont like explaining to the paramedics..............
Back to top
View user's profile
gelandangan
Super Member
Super Member


Joined: May 07, 2006
Posts: 5834
Location: Sydney Australia

PostPosted: Mon Feb 24, 2014 5:38 pm    Post subject: Re: RCBS ammoMaster Chrono repair. Reply with quote

I read on the web that there are a lot of these units gone dead within a few weeks off the warranty.
I guess most of them are having similar issues.

_________________
A straight line is the shortest distance between two points.
A smile is the shortest distance between two people.

The government I trust .. is my .45-70 Government.

Do - Not try!


gelandangan.weebly.com/
Back to top
View user's profile Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition
Page 1 of 1
All times are GMT - 7 Hours



Jump to:  


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Advertisements
 


Valid CSS! Valid HTML 4.01!
Click to check if this page is realy HTML 4.01 compliant for speed :)

All logos and trademarks in this site are property of HuntingNut.com.
The comments are property of their posters, all the rest © 2011 by HuntingNut.com
Interactive software released under GNU GPL, Code Credits, Privacy Policy

.: Upgraded to DragonFly 9.2 by Dizfunkshunal :.